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Abstract
The aim of this study was to determine the effects of olestra and sorbitol consumption on three accepted objective measures of diarrhea (stool output >250 g/day, liquid/watery stools, bowel movement frequency >3/day), and how stool composition influences reports of common gastrointestinal symptoms. A double-blind, placebo-controlled study compared the effects of sorbitol (40 g/day in candy), a poorly absorbed sugar-alcohol with known osmotic effects, with those of olestra (20 or 40 g/day in potato chips), a nonabsorbed fat, on objective measures of stool composition and GI symptoms. Sixty-six subjects resided on a metabolic ward for 12 days: 2 days lead-in, 4 days baseline, 6 days treatment. Sorbitol 40 g/day resulted in loose/liquid stools within 1-3 h of consumption. In contrast, olestra resulted in a dose-responsive stool softening effect after 2-4 days of consumption. Subjects reported "diarrhea" when mean stool apparent viscosity (peak force (PF), g) decreased from a perceived "normal" (mean +/- SE, 1355 +/- 224 g PF; firm stool) to loose (260 +/- 68 g PF) stool. Mean apparent viscosity of stool during treatment: placebo, 1363 +/- 280 g (firm); olestra 20 g/day 743 +/- 65 g (soft); olestra 40 g/day, 563 +/- 105 g (soft); and sorbitol 40 g/day, 249 +/- 53 g (loose). Of the 1098 stool samples collected, 38% (419/1098) were rated by subjects as "diarrhea," yet only 2% of treatment days (all in the sorbitol treatment group) met commonly accepted criteria for a clinical diarrhea. Sorbitol, but not olestra, increased the severity of abdominal cramping, urgency and nausea compared to placebo. Olestra consumption, at levels far in excess of normal snacking conditions, resulted in a gradual stool softening effect after several days of consumption, did not meet any of the three objective measures of diarrhea, and did not increase GI symptoms. Sorbitol consumption, at only 80% of the dose requiring a "laxative effect" information label, resulted in rapid onset loose/liquid stools and a significant increase in abdominal cramping, urgency and nausea. Overall, subjects categorized stool as "diarrhea" when stool decreased from their perceived "normal," but the vast majority of these reports were not associated with clinically significant diarrhea.
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... psyllium) that maintains its viscosity/water holding capacity throughout the large bowel [65] can have a dichotomous, 'stool normalizing' effect: decreasing the viscosity of hard stool in constipation (softer stool, increased transit rate, improved bowel movement frequency), and increasing the viscosity of loose/liquid stool in diarrhea (firmer stool, slower transit rate, less frequent bowel movements) [3,[66][67][68] . The gel-forming, water-holding capacity of psyllium has been shown to soften hard stool better than docusate, a marketed stool softener [59] , and to firm loose/liquid stool in diarrhea, normalizing stool form [66][67][68] . The stool normalizing benefit (e.g. ...
... Sensations ranging from mild discomfort to cramping pain, which can be associated with new/increased intake of dietary fiber, are viscosity-related events associated with an objective measure of stool viscosity, the "stool viscosity ratio" (SVR): highest stool viscosity divided by lowest stool viscosity within 24 hours [59] . A high amplitude propagating contraction that propels soft stool against more distal firm/hard stool can result in acute bowel wall distention (soft stool causes bowel wall to 'balloon' out), stimulating circumferential mechanoreceptors and causing discomfort/pain (much like balloon distention of the bowel wall in studies of pain threshold in patients with irritable bowel syndrome) [3,59] . ...
A primary function of the gastrointestinal tract is to provide the body with water, electrolytes and nutrients. It accomplishes this by ingestion, mechanical shearing, mixing and movement of the food through the gastrointestinal tract (motor events), secretion of digestive juices (≈ 6 liters per day) for degradation of complex nutrients into simple nutrients (e.g. complex carbohydrate into simple sugars), absorption of simple nutrients, water and electrolytes, and bacterial degradation of residue in the large bowel / elimination of waste. The small bowel is ≈ 7 meters long with a mucosa that is studded with millions of villi (each with microvilli), giving the small bowel a surface area approximately the size of a tennis court. Most digestion/absorption normally occurs early in the proximal small bowel. Non-digested/absorbed chyme arrives as a liquid in the cecum, and, under normal conditions, is gradually dehydrated as it slowly passes through the large bowel until it is eliminated as formed stool. Different types of dietary fiber can exert specific mechanical effects on each of these gastrointestinal functions, which can lead to local benefits (e.g. relief of constipation) as well as systemic benefits (e.g. cholesterol lowering, improved glycemic contro l ). Three characteristics of fiber (solubility, viscosity and fermentation) are predictive of the health benefits of different fiber types. Based on these three characteristics, dietary fiber can be divided into four clinically meaningful designations that support recommendations to address the specific healthcare needs of each patient. This review will describe the four clinically meaningful designations for dietary fiber, and provide a summary of the clinical studies that support the health benefits for each.
... The vast majority of anecdotal reports of diarrhoea are actually transient fluctuations in stool consistency and are of little or no clinical significance (429). Moreover, previous studies have revealed a discrepancy between recalled and recorded bowel habits (429)(430)(431). ...
... The vast majority of anecdotal reports of diarrhoea are actually transient fluctuations in stool consistency and are of little or no clinical significance (429). Moreover, previous studies have revealed a discrepancy between recalled and recorded bowel habits (429)(430)(431). It may be misleading to rely on patients recall as it is often imperfect (432) and ...
... The subjective presence or absence of diarrhoea was recorded in this study, but the results were not analysed in this study as patient's perception of diarrhoea does not correlate well with objective measures (429)(430)(431). However obtaining a valid gauge of diarrhoea would not have been possible from case note analysis. ...
... Abdominal discomfort and nausea may be associated with con- stipation. Clinical diarrhea is commonly defined as an elevated stool output (>200–250 g/day); watery, difficult to control bowel movements; and more than three bowel movements per day (McRorie et al., 2000 ). Some researchers used the term " laxation " to refer to a slight increase in the frequency of bowel movements and a softer consistency of feces (Livesey, 2001). ...
... Fecal collections allow investigators to measure frequency and consistency of bowel movements. Analysis of stool composition and weight (wet, dry, water, isolated nutrients) can identify subjects with diarrhea according to the clinical definition, based on weight, consistency, and frequency of bowel movements as discussed above and in McRorie et al. (2000). In addition, the presence of carbohydrate in the feces indicates carbohydrate malabsorption in the intestine, though this fecal analysis does not account for the amount of carbohydrate that is fermented in the large intestine. ...
... In another study, Clausen et al. (1998) compared the laxative effects of FOS to those of lactulose. Intakes of the LDCs were increased from 20–160 g per day until bowel movements reached more than 1000 g per day, which is four times the weight of criteria for clinical diarrhea (McRorie et al., 2000 ). The authors found that subjects could tolerate twice as much FOS as lactulose before the fermentation capacity of the microflora was exceeded: About 40 g FOS resulted in an average fecal volume of 238 +/− 38 g per day; 40 g of lactulose increased the fecal volume to 400 +/− 64 g per day, which is significantly higher than the fecal weight with FOS (Clausen et al., 1998). ...
Low-digestible carbohydrates (LDCs) are carbohydrates that are incompletely or not absorbed in the small intestine but are at least partly fermented by bacteria in the large intestine. Fiber, resistant starch, and sugar alcohols are types of LDCs. Given potential health benefits (including a reduced caloric content, reduced or no effect on blood glucose levels, non-cariogenic effect) the prevalence of LDCs in processed foods is increasing. Many of the benefits of LDCs are related to the inability of human digestive enzymes to break down completely the carbohydrates into absorbable saccharides and the subsequent fermentation of unabsorbed carbohydrates in the colon. As a result, LDCs may affect laxation and cause gastrointestinal effects, including abdominal discomfort, flatus, and diarrhea, especially at higher or excessive intakes. Such responses, though transient, affect the perception of the well-being of consumers and their acceptance of food products containing LDCs. Current recommendations for fiber intake do not consider total LDC consumption nor recommend an upper limit for LDC intake based on potential gastrointestinal effects. Therefore, a review of published studies reporting gastrointestinal effects of LDCs was conducted. We included only studies published in refereed journals in English. Additionally, we excluded studies of subjects with incomplete or abnormal functioning gastrointestinal tracts or where antibiotics, stimulant laxatives, or other drugs affecting motility were included. Only in studies with a control period, either placebo treatment or no LDC treatment, were included. Studies must have included an acceptable measure of gastrointestinal effect. Sixty-eight studies and six review articles were evaluated. This review describes definitions, classifications, and mechanisms of LDCs, evaluates published human feeding studies of fifteen LDCs for associations between gastrointestinal effects and levels of LDC intake, and presents recommendations for LDC consumption and further research.
... Feelings of bloating (as opposed to measurements of abdominal distension) are probably more common after overingestion of food in general, which is all too common. Furthermore, cramp appears to be secondary to faecal impaction in those with a poor bowel habit (McRorie et al. 2000), or in individuals with irritable bowel syndrome (Briet et al. 1995). In contrast to infectious diarrhoea, watery stools due to colonic fermentation of low-digestible carbohydrates are not a medical issue, and intakes of polyols comparable or greater than normal for dietary fibre are possible (Steinke et al. 1961;Sheinin et al. 1974;Spengler et al. 1987;Sinaud et al. 2002;A Lee, DN Storey, F Bornet and F Brouns, unpublished results). ...
... Rapid transition from a diet that encourages constipation (diets low in polyols, dietary fibre and some slimming diets) to ones that promote laxation (high polyol, dietary fibre and high food intakes) may be a transient cause of discomfort (see McRorie et al. 2000). This may be avoided by varying the daily intake of polyol-based foods gradually over a period of 1 to 4 weeks (see Steinke et al. 1961;Baker et al. 1999;Salford Symposium Consensus, 2001;Nurko et al. 2001). ...
... The scientific interpretation of consumer responses to polyols is difficult. Consumers generally indicate that they have diarrhoea whenever they notice a softening of their stool independently of whether it is inconveniencing and some 98 % of such occurrences do not meet commonly accepted criteria for clinical diarrhoea (McRorie et al. 2000). In agreement, a market survey of 1000 consumers of sugar-free products (polyols) has indicated that as little as 0·5 % of individuals make unprompted claims to the experience of adverse gastrointestinal responses (Stewart, 2001). ...
Abstract Polyols are hydrogenated carbohydrates used as sugar replacers. Interest now arises because of their multiple potential health benefits. They are non-cariogenic (sugar-free tooth-friendly), low-glycaemic (potentially helpful in diabetes and cardiovascular disease), low-energy and low-insulinaemic (potentially helpful in obesity), low-digestible (potentially helpful in the colon), osmotic (colon-hydrating, laxative and purifying) carbohydrates. Such potential health benefits are reviewed. A major focus here is the glycaemic index (GI) of polyols as regards the health implications of low-GI foods. The literature on glycaemia and insulinaemia after polyol ingestion was analysed and expressed in the GI and insulinaemic index (II) modes, which yielded the values: erythritol 0, 2; xylitol 13, 11; sorbitol 9, 11; mannitol 0, 0; maltitol 35, 27; isomalt 9, 6; lactitol 6, 4; polyglycitol 39, 23. These values are all much lower than sucrose 65, 43 or glucose 100, 100. GI values on replacing sucrose were independent of both intake (up to 50 g) and the state of carbohydrate metabolism (normal, type 1 with artificial pancreas and type 2 diabetes mellitus). The assignment of foods and polyols to GI bands is considered, these being: high (> 70), intermediate (> 55-70), low (> 40-55), and very low (< 40) including non-glycaemic; the last aims to target particularly low-GI-carbohydrate-based foods. Polyols ranged from low to very low GI. An examination was made of the dietary factors affecting the GI of polyols and foods. Polyol and other food GI values could be used to estimate the GI of food mixtures containing polyols without underestimation. Among foods and polyols a departure of II from GI was observed due to fat elevating II and reducing GI. Fat exerted an additional negative influence on GI, presumed due to reduced rates of gastric emptying. Among the foods examined, the interaction was prominent with snack foods; this potentially damaging insulinaemia could be reduced using polyols. Improved glycated haemoglobin as a marker of glycaemic control was found in a 12-week study of type 2 diabetes mellitus patients consuming polyol, adding to other studies showing improved glucose control on ingestion of low-GI carbohydrate. In general some improvement in long-term glycaemic control was discernible on reducing the glycaemic load via GI by as little as 15-20 g daily. Similar amounts of polyols are normally acceptable. Although polyols are not essential nutrients, they contribute to clinically recognised maintenance of a healthy colonic environment and function. A role for polyols and polyol foods to hydrate the colonic contents and aid laxation is now recognised by physicians. Polyols favour saccharolytic anaerobes and aciduric organisms in the colon, purifying the colon of endotoxic, putrefying and pathological organisms, which has clinical relevance. Polyols also contribute towards short-chain organic acid formation for a healthy colonic epithelium. Polyol tooth-friendliness and reduced energy values are affirmed and add to the potential benefits. In regard to gastrointestinal tolerance, food scientists and nutritionists, physicians, and dentists have in their independent professional capacities each now described sensible approaches to the use and consumption of polyols.
... In this group of non-constipated patients, who generally self-rated their stool consistency as midway between liquid and hard, moved their bowels daily or more often, and spent a median time at defecating of 5–6 minutes, the cramping pains associated with high pressure contractions as hypothesized by McRorie [3] did not seem highly prevalent during a PEG lavage preparation and were not influenced by use of psyllium powder. Urgency during the 4-hour lavage phase was the most notable side effect of the bowel preparation but was expected to some extent by all patients and thus may have been under-reported. ...
... Indeed, dietary or supplemental fiber is an essential element of colon health and bulk transit of stool. McRorie described a new objective measure "Stool Viscosity Ratio", a ratio of highest stool viscosity to lowest stool viscosity [3]. This was useful in explaining the origin of High Amplitude Propagating Contractions, motor activity of the colon felt to be primarily responsible for cramping pains when high volume luminal liquid meets solid stool. ...
... Medication canisters were weighed prior to distribution and upon return to further assess compliance. Tolerability of the four-day regimen (first hour of lavage, full volume of lavage, and overall tolerability of the regimen) evaluating bloating, gas, cramping, urgency, nausea and heartburn was assessed using a previously published visual analog scale from 0 (none) to 5 (extreme) [3]. During colonoscopy, a surgical endoscopist not involved in the endoscopy itself observed the entire procedure and assessed the quality of bowel preparation based on the worst portion of the exam using a scale of 1–7 to facilitate data analysis (Table 1). ...
Patients with new onset constipation or presumed hemorrhoid bleeding frequently require the use of both fiber supplements and diagnostic colonoscopy. We sought to determine whether preliminary fiber supplementation would alter the tolerability or efficacy of a standard bowel preparation for colonoscopy
A prospective, double blind, randomized trial was designed to compare a short course of a psyllium-based supplement versus placebo prior to a colon lavage. Patients were given an unlabeled canister of powder, and instructed to take 1 tablespoon with 8 oz of water bid for 4 days before colonoscopy. A 4-liter polyethylene based glycol lavage was self-administered over 4 hours on the day prior to colonoscopy. A questionnaire on pre-study bowel habits and side effects was completed. Efficacy of the preparation was visually evaluated on a pre-determined scale.
There were no significant differences between the two groups in gender, race, age, pre-study stool frequency or consistency. Tolerability was equivalent but efficacy of the bowel preparation was worse in the psyllium group compared to placebo (P < 0.05).
In non-constipated patients psyllium based fiber supplementation should not be initiated in the few days prior to endoscopy using a polyethylene glycol preparation.
... 33 Dietary fiber has been the subject of much research on the impact on gut microbiota, gut motility and constipation, however, fruits contain several other components that may impact the intestinal lumen environment and they will be discussed below. [34][35][36][37][38][39] Dietary fiber Several fruits are excellent sources of dietary fiber. 30 Fiber is defined as the sum of carbohydrates that are polymers of three or more monomeric units and are not digested or absorbed in the small intestine, plus lignins. ...
... In a randomized controlled trial (RCT), 40 g per day sorbitol for 6 days resulted in significantly greater fecal water and fecal weight compared to placebo. 39 Furthermore, unabsorbed sorbitol reaches the colon where it is fermented by the gut microbiota, increasing SCFA production, 51 and possibly altering the microbiota. While this hypothesis has not been tested in humans, sorbitol in rats increased fecal, colonic and cecal Lactobacillus sp. ...
Fruits are the seed-bearing product of plants and have considerable nutritional importance in the human diet. The consumption of fruits is among the dietary strategies recommended for constipation due to its potential effects on the gut microbiota and gut motility. Dietary fiber from fruits has been the subject of research on the impact on gut microbiota, gut motility and constipation, however, fruits also contain other components that impact the intestinal luminal environment that may impact these outcomes including sorbitol and (poly)phenols. This review aims to explore the mechanisms of action and effectiveness of fruits and fruit products on the gut microbiota, gut motility and constipation, with a focus on fiber, sorbitol and (poly)phenols. In vitro, animal and human studies investigating the effects of fruits on gut motility and gut microbiota were sought through electronic database searches, hand searching and consulting with experts. Various fruits have been shown to modify the microbiota in human studies including blueberry powder (lactobacilli, bifidobacteria), prunes (bifidobacteria), kiwi fruit (Bacteroides, Faecalibacterium prausnitzii) and raisins (Ruminococcus, F. prausnitzii). Prunes, raisins and apple fiber isolate have been shown to increase fecal weight in humans, whilst kiwifruit to increase small bowel and fecal water content. Apple fiber isolate, kiwifruit, fig paste, and orange extract have been shown to reduce gut transit time, while prunes have not. There is limited evidence on which fruit components play a predominant role in regulating gut motility and constipation, or whether a synergy of multiple components is responsible for such effects.
... Each of these substances alter bowel habit and stool characteristics to some extent, albeit by different mechanisms. (22,23) It was reported (22) in pigs that consumption of olestra decreased stool water content but the stool softening effect was found to be dose responsive, (23) and there was no resulting oily or liquid stool even with the consumption of 80 g/d. In human Downloaded by [University of Jiangnan] at 06:06 23 October 2017 studies, consumption of olestra at a rate of 40 g/d (i.e., excess of usual snacking conditions) resulted in excess fat excretion similar to the symptoms of steatorrhea (24) but did not result in significant increase in stool output. ...
... Each of these substances alter bowel habit and stool characteristics to some extent, albeit by different mechanisms. (22,23) It was reported (22) in pigs that consumption of olestra decreased stool water content but the stool softening effect was found to be dose responsive, (23) and there was no resulting oily or liquid stool even with the consumption of 80 g/d. In human Downloaded by [University of Jiangnan] at 06:06 23 October 2017 studies, consumption of olestra at a rate of 40 g/d (i.e., excess of usual snacking conditions) resulted in excess fat excretion similar to the symptoms of steatorrhea (24) but did not result in significant increase in stool output. ...
Olestra is a sucrose polyester, the first fat substitute that replaces many of the uses of dietary fat such as in dough conditioning, in sprays, in filling ingredients, in flavors, as well as in frying. However, it is not absorbed in the human digestive system, and therefore, it does not provide any nutrition or energy. It has taste and cooking properties similar to the conventional fats and oils. FDA approved the use of olestra only in limited and specific foods with a listing of fat soluble vitamins (vitamins A, D, E, and K) in the ingredient statement of olestra-containing foods followed by an asterisk that is linked to the statement “Dietarily insignificant.” This article reviews the physiological, nutritional, health, and environmental effects of the human consumption of olestra.
... Olestra, used in snacks such as potato chips and crackers, is a lipid that possesses properties of conventional fats, but is neither digested nor absorbed [90]. Although diarrhoea was a common complaint by the consumers, an RCT using higher than consumption doses did not show an increase in stool frequency, but showed a modest stool softening effect in subjects compared to the controls [90]. ...
... Olestra, used in snacks such as potato chips and crackers, is a lipid that possesses properties of conventional fats, but is neither digested nor absorbed [90]. Although diarrhoea was a common complaint by the consumers, an RCT using higher than consumption doses did not show an increase in stool frequency, but showed a modest stool softening effect in subjects compared to the controls [90]. ...
The aetiology of diarrhoea can often be simple to identify, but in some cases may pose a challenge. The diagnosis of drug-induced diarrhoea can easily be sorted based on timing of the symptom with onset of a new drug. Treatment can vary from simply monitoring and eventual resolution with continuation of the drug, to discontinuation of the offending agent. In cases where a drug cannot always be stopped, additional medications can help control the symptom. Factitious diarrhoea can present a diagnostic challenge if the evaluating physician does not suspect its possibility. Typically a careful history, and in some cases, stool testing can provide clues. The diagnosis of idiopathic diarrhoea is often made when exhaustive testing provides no definite aetiology and the goal of management is supportive care and symptomatic treatment.
... This outcome was chosen since PEG-ELS, the standard of care in many centers, is accepted as being highly effective [1,2,10] and changing from PEG-ELS would thus occur only in the setting of better tolerability. Our assessment of tolerability was undertaken using a tolerability questionnaire (Appendix 1) that, in the absence of a well-validated tool, was based on indices successfully used in previous trials of bowel cleanout [8,11,12]. Tolerability was defined as a more general concept than satisfaction, that encompassed all the issues related to the patient in addition to satisfaction, including ease of drinking, taste, fullness, nausea, pain, and quality of sleep. No single outcome measure or tool is available to summarize these responses into one valid and reliable tolerability score. ...
... A required sample size of 41 patients per group was calculated to detect a difference of one point on the satisfaction Likert scale between the two groups in the primary outcome, assuming α = 0.05, 90 % power and a standard deviation (SD) of 1.4, as previously found [11]. Assuming 10 % dropout rate, we planned to enrol 90 patients in total. ...
Comparison of bowel preparation for colonoscopy in children with either Pico-Salax (sodium picosulphate with magnesium citrate) or polyethylene glycol with electrolyte solution (PEG-ELS).
In this investigator-blinded, randomized controlled trial, 83 children (12.5 +/- 3.1 years) requiring elective colonoscopy at a referral hospital were randomly allocated to Pico-Salax (n = 43) or PEG-ELS (n = 40), and an intention-to treat analysis was applied. Pico-Salax was administered in two doses, one the evening before and one on the morning of the procedure. PEG-ELS was administered over 4 hours. Efficacy was scored using the Ottawa scale and other constructs. Tolerability and toxicity were measured by patient and nursing questionnaires and serum biochemistry.
35 of Pico-Salax patients (81 %) were satisfied or very satisfied with the cleanout, compared with 19 (48 %) in the PEG-ELS group (P = 0.001). No differences were found in bowel cleanout effectiveness, as judged by the Ottawa score (P = 0.24), completion rates (P = 0.69), colonoscopy duration (P = 0.59), need for enemas (P = 0.25), or physician's global impression (P = 0.7). Except for one case of mild dehydration in the Pico-Salax group, no clinically significant adverse events were recorded. Serum biochemistry results were similar between groups except for more hypermagnesemia associated with Pico-Salax and hypokalemia with PEG-ELS; neither was clinically significant.
Children tolerate Pico-Salax better than PEG-ELS for bowel cleanout before colonoscopy. This study did not demonstrate superiority of effectiveness or safety for either regimen.
... 7 Olestra, a non-digested, non-absorbed fat, has also been shown to exert a dose-responsive stool softening/stool bulking effect at doses far exceeding normal snacking conditions after several days of consumption, but it is not clear how this effect compares to dietary ®bre. 10 The aim of this study was to determine the effects of dietary ®bre and olestra on regional dehydration and apparent viscosity of digesta residue throughout the large bowel. ...
... 1 This is in contrast to olestra, which exhibits a similar stool softening effect compared to dietary ®bre, but decreases the percentage stool water content and increases stool output by only 1 g for every gram consumed. 9,10 As discussed earlier, stool apparent viscosity is highly sensitive to relatively small changes in water content. An increase in stool water content of 3.6% for dietary ®bre 80 g/day (eight daily doses) compared to control resulted in a 37.6% reduction in stool apparent viscosity. ...
Increased consumption of non-digested, non-absorbed substrates, such as dietary fibre, can lead to an increase in colonic transit rate and stool output. The effects of dietary fibre and olestra on the consistency and water content of digesta residue within the large bowel were not known.
The aim of this study was to determine the effects of dietary fibre and olestra on regional dehydration and apparent viscosity of digesta residue throughout the large bowel.
Seventy-eight pigs were fed diet alone (control) or supplemented with 40 g/day or 80 g/day dietary fibre or olestra and sacrificed 24, 48, 96 or 192 h after initiation of dosing. The large bowel was removed, divided into 13 segments, and the digesta residue/stool was analysed for apparent viscosity (peak force for extrusion) and percentage water content.
In control animals, digesta residue occurred as a continuum, from liquid in the cecum (87.9% water) to solid in the rectum (71. 5% water). The relatively small decrease in percentage water content (16.4%) resulted in a marked increase in mean apparent viscosity (liquid = 87 g peak force; solid=3919 g peak force). Dietary fibre increased the percentage water content of digesta residue throughout the large bowel. In contrast, olestra decreased the percentage water content of digesta residue in the mid and distal large bowel. At 40 g/day, dietary fibre showed a significant (P < 0.05) digesta residue/stool softening effect for all time points, beginning at 24-h (single dose). Olestra 40 g/day did not significantly soften digesta residue/stool until 48 h (2 doses, P < 0.05), and was not different from control at 96 h. At 80 g/day, both dietary fibre and olestra significantly (P < 0.01) softened digesta residue/stool at all time points. There were no liquid or oily stools at any dose or time-point.
Relatively small changes in water content result in large changes in digesta residue/stool apparent viscosity. Dietary fibre increased digesta residue/stool water content throughout the bowel, resulting in softer digesta residue/stool. In contrast, olestra decreased stool water content, yet had a similar stool softening effect compared to dietary fibre.
... Sorbitol is a beneficial nutrient contained in fruits. Dietary sorbitol cannot be digested and absorbed and has the ability to hold water in its molecules (47,48). Several studies have shown that sorbitol significantly increased fecal water or fecal weight and then eased constipation (49). ...
Functional constipation (FC) is commonly treated with fruits whose efficacy remains unclear. We conducted a meta-analysis of fruit intervention for FC and provided evidence-based recommendations. We searched seven databases from inception to July 2022. All randomized and crossover studies on the effectiveness of fruits on FC were included. We conducted sensitivity and subgroup analysis. A total of 11 studies were included in this review. Four trials showed that kiwifruits have significantly increased stool frequency (MD = 0.26, 95% CI (0.22, 0.30), P < 0.0001, I ² = 0%) than palm date or orange juice in the fixed-effect meta-analysis. Three high-quality studies suggested that kiwifruits have a better effect than ficus carica paste on the symptom of the FC assessed by the Bristol stool scale in the fixed-effect meta-analysis [MD = 0.39, 95% CI (0.11, 0.66), P < 0.05, I ² = 27%]. Besides, five trials showed that fruits can increase the amount of Lactobacillus acidophilus [MD = 0.82, 95% CI (0.25, 1.39), P < 0.05, I ² = 52%], analyzed with the random-effect model. Subgroup meta-analysis based on the types of fruits suggested that fruits including pome fruit, citrus fruit, and berries have increased the effect of Bifidobacterium t more than the stone fruits in the random effect meta-analysis [MD = 0.51, 95% CI (0.23, 0.79), P < 0.05, I ² = 84%]. Totally, fruit intake may have potential symptom alleviation on the FC as evidence shows that they can affect stool consistency, stool frequency, and gut microbiota. Further large-scale studies are needed to gain more confident conclusions concerning the association between fruit intake and FC in the future.
... The mild laxative effects of plum could be attributed to the synergistic effect provided by dietary fibre, sorbitol and polyphenols (Attaluri et al. 2011). Studies showed that the consumption of sorbitol had a stool-softening effect in small doses but could quickly change the fluid balance in the colon due to its osmotic effects in high doses (McRorie et al. 2000). Sorbitol could also affect gut motility because of its prebiotic effect. ...
All details about our chapter are available here:
https://www.routledge.com/Handbook-of-Plum-Fruit-Production-Postharvest-Science-and-Processing/Gull-Nayik-Wani-Nanda/p/book/9781032062426#
... The mild laxative effects of plum could be attributed to the synergistic effect provided by dietary fibre, sorbitol and polyphenols (Attaluri et al. 2011). Studies showed that the consumption of sorbitol had a stool-softening effect in small doses but could quickly change the fluid balance in the colon due to its osmotic effects in high doses (McRorie et al. 2000). Sorbitol could also affect gut motility because of its prebiotic effect. ...
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... When considering ''dietary fiber'' (intrinsic and intact in whole foods), it is unclear how much of an observed health effect can actually be attributed to a direct effect of the dietary fiber in the gut, versus other dietary constituents like sorbitol, a sugar alcohol with an osmotic laxative effect that is independent of fiber (e.g., prunes have both high fiber content and high sorbitol content, yet prune juice has a similar laxative effect without the fiber) [1,7,8]. Much of the evidence supporting the health benefits of dietary fiber is derived from epidemiologic studies, which can be useful for establishing ''associations'' between consumption of high-fiber diets and observed health effects (or low-fiber diets and increased risk of disease), but lack the control necessary to establish causation. ...
Background
Misconceptions about the effects of dietary fiber and ?functional? fiber on stool parameters and constipation persist in the literature. MethodsA comprehensive literature review was conducted with the use of the Scopus and PubMed scientific databases to identify and objectively assess well-controlled clinical studies that evaluated the effects of fiber on stool parameters and constipation. ResultsThe totality of well-controlled randomized clinical studies show that, to exert a laxative effect, fiber must: (1) resist fermentation to remain intact throughout the large bowel and present in stool, and (2) significantly increase stool water content and stool output, resulting in soft/bulky/easy-to-pass stools. Poorly fermented insoluble fiber (e.g., wheat bran) remains as discreet particles which can mechanically irritate the gut mucosa, stimulating water & mucous secretion if the particles are sufficiently large/coarse. For soluble fibers, some have no effect on viscosity (e.g., inulin, wheat dextrin) while others form high viscosity gels (e.g., ?-glucan, psyllium). If the soluble fiber is readily fermented, whether non-viscous or gel-forming, it has no effect on stool output or stool water content, and has no laxative effect. In contrast, a non-fermented, gel-forming soluble fiber (e.g., psyllium) retains its gelled nature and high water-holding capacity throughout the large bowel, resulting in soft/bulky/easy-to-pass stools. Conclusion
When considering a recommendation for a fiber supplement regimen to treat and/or prevent constipation, it is important to consider which fibers have the physical characteristics to exert a laxative effect, and which fiber supplements have rigorous clinical evidence of a significant benefit in patients with constipation.
... In normal individuals, this propulsion is not typically perceived unless it causes stool to fill the rectum, stimulating an urge to defecate. 3,4,67 In contrast, if a propagating contraction causes a bolus of lower-viscosity fiberrich stool to collide with more distal formed/hard stool, the lower-viscosity fiber-rich stool deforms to cause acute dilation of the bowel, stretching mechanoreceptors and causing sensations of discomfort to cramping pain. The discomfort/ pain would be transient, occurring with the frequency of propagating contractions, and relieved with a bowel movement. ...
Dietary fiber that is intrinsic and intact in fiber-rich foods (eg, fruits, vegetables, legumes, whole grains) is widely recognized to have beneficial effects on health when consumed at recommended levels (25 g/d for adult women, 38 g/d for adult men). Most (90%) of the US population does not consume this level of dietary fiber, averaging only 15 g/d. In an attempt to bridge this "fiber gap," many consumers are turning to fiber supplements, which are typically isolated from a single source. Fiber supplements cannot be presumed to provide the health benefits that are associated with dietary fiber from whole foods. Of the fiber supplements on the market today, only a minority possess the physical characteristics that underlie the mechanisms driving clinically meaningful health benefits. In this 2-part series, the first part (previous issue) described the 4 main characteristics of fiber supplements that drive clinical efficacy (solubility, degree/rate of fermentation, viscosity, and gel formation), the 4 clinically meaningful designations that identify which health benefits are associated with specific fibers, and the gel-dependent mechanisms in the small bowel that drive specific health benefits (eg, cholesterol lowering, improved glycemic control). The second part (current issue) of this 2-part series will focus on the effects of fiber supplements in the large bowel, including the 2 mechanisms by which fiber prevents/relieves constipation (insoluble mechanical irritant and soluble gel-dependent water-holding capacity), the gel-dependent mechanism for attenuating diarrhea and normalizing stool form in irritable bowel syndrome, and the combined large bowel/small bowel fiber effects for weight loss/maintenance. The second part will also discuss how processing for marketed products can attenuate efficacy, why fiber supplements can cause gastrointestinal symptoms, and how to avoid symptoms for better long-term compliance.
... Sensations from slight discomfort and the urge to defecate to cramping pain are also strongly correlated with high-amplitude propagating contractions (HAPCs; Lembo et al., 1997;Zighboim et al., 1995), suggesting that physiologic colonic motor events can give rise to these sensations. Studies conducted with healthy subjects demonstrated that sensations of cramping pain were associated with the passage of formed stool followed by loose/liquid stool, objectively characterized as a high "stool viscosity ratio" (highest viscosity stool value divided by the lowest viscosity stool value in a given day; Marlett et al., 2000;McRorie, Zorich, et al., 2000). In the large bowel, HAPCs (peristalsis) have been correlated with mass movements, propelling luminal contents toward the rectum (Crowell, Bassotti, Cheskin, Schuster, & Whitehead, 1991;McRorie, Greenwood-Van Meerveld, & Rudolph, 1998;Sarna, 1993). ...
Purpose: This review focuses on the health benefits of viscous versus nonvis-cous soluble fibers, why symptoms can occur with increased fiber consumption , and how to avoid symptoms to improve adherence with a high-fiber diet.
... While small amounts of sorbitol have a humectant, stoolsoftening effect, large doses rapidly change fluid balance in the colon due to an osmotic effect. When the liquid stool is pushed behind hard stool by high-amplitude propagating contractions, the liquid portion exerts pressure on the bowel wall, like an inflating balloon, and may cause a severe cramping pain (McRorie et al., 2000). Solid sources are slower to cause diarrhea than liquids, divided doses are better tolerated, and an adaptation to slowly increasing doses may occur. ...
This paper describes composition of dried plums and their products (prune juice and dried plum powder) with special attention to possibly bioactive compounds. Dried plums contain significant amounts of sorbitol, quinic acid, chlorogenic acids, vitamin K1, boron, copper, and potassium. Synergistic action of these and other compounds, which are also present in dried plums in less conspicuous amounts, may have beneficial health effects when dried plums are regularly consumed. Snacking on dried plums may increase satiety and reduce the subsequent intake of food, helping to control obesity, diabetes, and related cardiovascular diseases. Despite their sweet taste, dried plums do not cause large postprandial rise in blood glucose and insulin. Direct effects in the gastrointestinal tract include prevention of constipation and possibly colon cancer. The characteristic phenolic compounds and their metabolites may also act as antibacterial agents in both gastrointestinal and urinary tracts. The indirect salutary effects on bone turnover are supported by numerous laboratory studies with animals and cell cultures. Further investigation of phenolic compounds in dried plums, particularly of high molecular weight polymers, their metabolism and biological actions, alone and in synergy with other dried plum constituents, is necessary to elucidate the observed health effects and to indicate other benefits.
... For example, a recent prospective, randomized-controlled 8-week single-blind crossover study examined treatment with dried plums (prunes, 6 g / day fi ber) compared with psyllium (6 g / day fi ber) in 40 patients ( 99 ). Dried plums not only contain fi ber but also sorbitol and fructans, non-absorbable carbohydrates that, when fermented by colonic bacteria, create an osmotic load that can dramatically alter stool frequency and consistency ( 100 ). Treatment with dried plums resulted in a greater improvement in constipation symptoms as refl ected by a signifi cant increase in the number of complete spontaneous bowel movements and in stool consistency (soft er stools) when compared to treatment with psyllium. ...
Despite years of advising patients to alter their dietary and supplementary fiber intake, the evidence surrounding the use of fiber for functional bowel disease is limited. This paper outlines the organization of fiber types and highlights the importance of assessing the fermentation characteristics of each fiber type when choosing a suitable strategy for patients. Fiber undergoes partial or total fermentation in the distal small bowel and colon leading to the production of short-chain fatty acids and gas, thereby affecting gastrointestinal function and sensation. When fiber is recommended for functional bowel disease, use of a soluble supplement such as ispaghula/psyllium is best supported by the available evidence. Even when used judiciously, fiber can exacerbate abdominal distension, flatulence, constipation, and diarrhea.Am J Gastroenterol advance online publication, 2 April 2013; doi:10.1038/ajg.2013.63.
... Sensations from slight discomfort and the urge to defecate to cramping pain are also strongly correlated with high-amplitude propagating contractions (HAPCs; Lembo et al., 1997;Zighboim et al., 1995), suggesting that physiologic colonic motor events can give rise to these sensations. Studies conducted with healthy subjects demonstrated that sensations of cramping pain were associated with the passage of formed stool followed by loose/liquid stool, objectively characterized as a high "stool viscosity ratio" (highest viscosity stool value divided by the lowest viscosity stool value in a given day; Marlett et al., 2000;McRorie, Zorich, et al., 2000). In the large bowel, HAPCs (peristalsis) have been correlated with mass movements, propelling luminal contents toward the rectum (Crowell, Bassotti, Cheskin, Schuster, & Whitehead, 1991;McRorie, Greenwood-Van Meerveld, & Rudolph, 1998;Sarna, 1993). ...
This review focuses on the health benefits of viscous versus nonviscous soluble fibers, why symptoms can occur with increased fiber consumption, and how to avoid symptoms to improve adherence with a high-fiber diet.
Review of scientific literature as well as evidence-based guidelines and resources.
While it is generally known that "fiber is good for you," it is less well known that specific health benefits are associated with specific fiber characteristics. Many of the health benefits of fiber can be directly correlated with the viscosity of soluble fibers when hydrated (i.e., gel-forming). A reduction in viscosity of a given fiber will attenuate these health benefits, and a nonviscous fiber does not exhibit these health benefits.
Increasing the viscosity of chyme with a viscous soluble fiber has been shown clinically to lower cholesterol for cardiovascular health, improve glycemic control in type 2 diabetes, normalize stool form in both constipation (softens hard stool) and diarrhea (firms loose/liquid stool), and improve the objective clinical measures of metabolic syndrome (glycemic control, lipoprotein profile, body mass index/weight loss, and blood pressure).
... 2 Sorbitol is poorly absorbed in the upper GI tract (hence the 'sugar-free' designation), and has been known for decades to have a dose-responsive laxative effect with the potential for bloating, abdominal cramping and diarrhoea with as little as 10-20 g. 2, 3 A single serving (1.7 oz) of a sugar-free candy (sorbitol 40 g) resulted in abdominal cramping, urgency and a >4-fold increase in stool output with significant water ⁄ electrolyte loss and liquid stools within 2 h of consumption. 4 However, the FDA does not require a warning label for a potential 'laxative effect' unless 'reasonably foreseeable consumption may result in a daily ingestion of 50 g of sorbitol' (per product). ...
... Although no adverse effect of Sorb was found in the dogs consuming either the 100 or 200% AI diets, McRorie et al. (30) found that consumption of 40 g/day Sorb by humans resulted in loose, liquid stools and abdominal cramping. In contrast, dogs were able to tolerate a similar daily dose (∼50 g/day) of Sorb well without experiencing diarrhea. ...
The objective was to quantify in vitro digestion, true metabolizable energy (TME(n)) content, glycemic and insulinemic responses, and gastrointestinal tolerance to fructose (Fruc), maltodextrin (Malt), polydextrose (Poly), pullulan (Pull), resistant starch (RS), sorbitol (Sorb), and xanthan gum (Xan). Limited digestion of RS, Poly, and Xan occurred. Fruc, Malt, and Sorb resulted in the highest (P < 0.05) TME(n) values, Pull was intermediate, and RS and Poly were lowest. Malt had the highest (P < 0.05) area under the curve for glucose and insulin in the glycemic tests. Gastrointestinal tolerance was examined for diets containing carbohydrates at either 100 or 200% of the adequate intake (AI) value for dietary fiber. At 100% and 200% AI, Malt, RS, and Sorb resulted in ideal fecal scores, while Pull and Xan resulted in looser stools and Poly resulted in diarrhea. The carbohydrates studied varied widely in physiological outcomes. Certain carbohydrates could potentially benefit large bowel health.
... 28 -31 Intake of olestra did not increase objective measures of diarrhea (stool output of Ͼ250 g/d, liquid or water stool, or Ͼ3 bowel movements per day). 28 However, consumption of 40 g of olestra in Ϸ5 oz of chips (15 chips are Ϸ1 oz) can increase fecal fat excretion and result in a misdiagnosis of malabsorption. 29 Consumption of olestra does not seem to exacerbate quiescent inflammatory bowel disease. ...
The purpose of this Advisory is to review potential effects of fat substitutes on achieving the American Heart Association (AHA) dietary recommendations for fat intake and to examine the potential effects of fat substitutes on health. Fat substitutes are compounds incorporated into food products to provide them with some of the qualities of fat. Trends in dietary fat intake and the composition and labeling of fat substitutes also will be reviewed.
The AHA recommends limiting total fat intake to ≤30% of calories and saturated fats to <10% of total energy intake for the population as a whole. The AHA also recommends that those with elevated LDL cholesterol levels or cardiovascular disease restrict saturated fats to <7% of calories.1 To achieve a more healthful dietary pattern in the United States, current dietary guidelines recommend increasing intake of fruits, vegetables, and grains and modifying the type and amount of fat consumed.1,2⇓ The emphasis is on achieving an overall healthful pattern of eating rather than on limiting the focus to merely achieving goals for macronutrient composition.
Americans are responding to the dietary recommendations. The proportion of calories derived from fat in the United States is decreasing.3,4⇓ Data from part one of the National Health and Nutrition Examination Survey (NHANES) III conducted from 1988 to 1991 indicated that in the American diet, 34% of calories were from fat, which is lower than previous estimates of 40% to 42% in the 1950s.3 Data from the National Food Consumption Survey and the Continuing Survey of Food Intake of Individuals (CSFII) are more mixed, with a downward trend between 1965 and 1988 and a shift upward by 1994 to 1995.4 Nonetheless, efforts to reduce or modify fat intake seem to continue.
In the food supply, 30% of the total fat …
... There is a discrepancy between the clinical definition and popular understanding. Commonly accepted criteria for clinical diarrhea are (1) elevated stool output (>200-250 g/day); (2) watery, difficult to control bowel movements; and (3) frequency of bowel movements exceeding 3 per day (McRorie et al., 2000). In the McRorie et al. study, when placebo, olestra, or sorbitol was administered to 66 subjects, 38% of the bowel movements in the study were rated by the subjects as ''diarrhea'', yet only 2% of treatment days met the commonly accepted criteria for clinical diarrhea. ...
Polydextrose is a non-digestible 1 kcal/g polysaccharide used primarily as a sugar replacer and dietary fiber in foods. At typical use levels, polydextrose provides physiological effects similar to those of other dietary fibers. However, excessive consumption of non-digestible carbohydrates can lead to gastrointestinal distress. Nine clinical studies were conducted with polydextrose to evaluate the extent of such symptoms. These studies determined laxation endpoints in adults and children, and showed that polydextrose was better tolerated than most other low digestible carbohydrates (e.g. polyols). This is because of a higher molecular weight and partial colonic fermentation, leading to a lower risk of osmotic diarrhea. After evaluating these studies, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the European Commission Scientific Committee for Food (EC/SCF) concluded that polydextrose has a mean laxative threshold of approximately 90 g/d (1.3 g/kg bw) or 50 g as a single dose.
... In the fasting state, these symptoms typically occur within 4 h of ingesting as little as 10 g of sorbitol. [2][3][4][5] Sorbitol is also widely used as an osmotic laxative for treating constipation. Because sorbitol is cheaper than lactulose, it is preferred by several formularies for treating constipation in the elderly. ...
It is unknown if sorbitol, a widely used laxative agent, accelerates colonic transit, and if these effects are modified by concomitant meal ingestion. Colonic transit was assessed by (111)In scintigraphy in 40 healthy subjects. After a 24-h scan, subjects received sorbitol (30 mL of 70% solution) or dextrose (30 mL of 70% solution), administered with or without a meal. Colonic transit, breath hydrogen excretion, and symptom scores were recorded for 4 h thereafter. VAS scores for flatulence, but not other symptoms increased (P = 0.004) by 13.1 +/- 6.3 mm (mean +/- SEM) on a 100 mm scale after sorbitol alone or sorbitol with a meal (by 18.9 +/- 7.2 mm), but not after dextrose. After adjusting for GC(24), sorbitol accelerated (P < 0.001) colonic transit (GC(28) = 3.0 +/- 0.3) compared with dextrose (GC(28) = 2.2 +/- 0.2), regardless of meal ingestion. Breath hydrogen excretion was correlated with the change in colonic transit (r = 0.52, P < 0.01) and with flatulence (r = 0.45, P = 0.003) after sugar ingestion. In healthy subjects, sorbitol accelerated colonic transit and increased flatulence but not other symptoms within 4 h, regardless of meal intake.
Drug‐induced diarrhea is frequently suspected in patients who develop it soon after starting a new medication. Diarrhea can be broadly categorized based on the following stool characteristics: watery, a category that includes changes in ion transport, or increased motility inflammatory, and fatty. Osmotic diarrheas can occur from intentional use of a drug as part of its mechanism of action, or unintentionally. Secretory diarrhea, in contrast to osmotic diarrhea, produces voluminous stools that persist despite fasting. It has been speculated that anticholinergic drugs, which most often cause constipation by reducing intestinal motility, and the proton pump inhibitor omeprazole, can cause watery diarrhea. Most cases of drug‐induced diarrhea resolve spontaneously within a few days after withdrawal of the drug, or with dose reduction. If diarrhea is severe or persistent, patient management should include replenishment of any fluid and electrolyte deficits with oral hydration or, if warranted, with intravenous fluids.
Plecanatide, a uroguanylin analog, activates the guanylate cyclase C receptors in the epithelial lining of the gastrointestinal tract in a pH-dependent fashion initiating (1) the conversion of intracellular guanosine triphosphate to cyclic guanosine monophosphate, which increases the activity of the cystic fibrosis transmembrane conductance regulator to increase chloride and bicarbonate secretion into the intestinal lumen and (2) a decrease in activity of the sodium-hydrogen ion exchanger. The resulting ionic shifts cause an increase in lumenal fluid to facilitate digestion. Plecanatide has been approved by the FDA for use in chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation. This manuscript is a critical assessment of the therapeutic efficacy and potential risks associated with the use of plecanatide in CIC. The discussion of CIC as a clinical and investigative disorder focuses on the importance of this problem as well and the difficulties involved in clinical management and scholarly investigation of a symptom arising from multiple pathophysiologic mechanisms. Clinical data from studies of recently approved drugs for CIC are utilized to construct a platform for thoughtful understanding of CIC and of how changes in investigation guidelines influence the interpretation of study data and guide symptom management. Plecanatide is a safe and effective medication for the management of adults with CIC.
Enduring misconceptions about the physical effects of fiber in the gut have led to misunderstandings about the health benefits attributable to insoluble and soluble fiber. This review will focus on isolated functional fibers (eg, fiber supplements) whose effects on clinical outcomes have been readily assessed in well-controlled clinical studies. This review will also focus on three health benefits (cholesterol lowering, improved glycemic control, and normalizing stool form [constipation and diarrhea]) for which reproducible evidence of clinical efficacy has been published. In the small bowel, clinically meaningful health benefits (eg, cholesterol lowering and improved glycemic control) are highly correlated with the viscosity of soluble fibers: high viscosity fibers (eg, gel-forming fibers such as b-glucan, psyllium, and raw guar gum) exhibit a significant effect on cholesterol lowering and improved glycemic control, whereas nonviscous soluble fibers (eg, inulin, fructooligosaccharides, and wheat dextrin) and insoluble fibers (eg, wheat bran) do not provide these viscosity-dependent health benefits. In the large bowel, there are only two mechanisms that drive a laxative effect: large/coarse insoluble fiber particles (eg, wheat bran) mechanically irritate the gut mucosa stimulating water and mucous secretion, and the high water-holding capacity of gel-forming soluble fiber (eg, psyllium) resists dehydration. Both mechanisms require that the fiber resist fermentation and remain relatively intact throughout the large bowel (ie, the fiber must be present in stool), and both mechanisms lead to increased stool water content, resulting in bulky/soft/easy-to-pass stools. Soluble fermentable fibers (eg, inulin, fructooligosaccharide, and wheat dextrin) do not provide a laxative effect, and some fibers can be constipating (eg, wheat dextrin and fine/smooth insoluble wheat bran particles). When making recommendations for a fiber supplement, it is essential to recognize which fibers possess the physical characteristics required to provide a beneficial health effect, and which fiber supplements are supported by reproducible, rigorous evidence of one or more clinically meaningful health benefits.
Drug induced diarrheaWatery diarrheaInflammatory diarrheaFatty diarrheaConclusion
References
OBJECTIVE:The aim of this study was to compare the effects of two nondigested, nonabsorbed dietary components on objective and subjective measures of gastrointestinal (GI) function.METHODS:A placebo-controlled parallel study compared the effects of wheat bran (20 g/day or 40 g/day in cereal), a well-known dietary fiber, with those of olestra (20 g or 40 g/day in potato chips), a nonabsorbed fat, on stool output, stool apparent viscosity (log peak force for extrusion [PF]), stool water content, and GI symptoms. Sixty subjects resided on a metabolic ward for 9 days: 3 days baseline and 6 days treatment.RESULTS:Compared with placebo, consumption of 20 g/day wheat bran for 6 days resulted in a rapid (within 38 h) increase in mean (±SE) stool output (placebo, 150 ± 29 g/day; bran, 246 ± 35 g/day, p < 0.05), a directional increase in mean stool water content (placebo, 81.2 ± 0.8%; bran, 83.9 ± 0.8%), stool water output (placebo, 159 ± 54 g/day; bran, 238 ± 30 g/day), and bowel movement frequency (BM/day) (placebo, 2.2 ± 0.4; bran, 2.6 ± 0.4), and no stool-softening effect (placebo log PF, 2.9 ± 0.1 g; bran log PF, 2.9 ± 0.1 g). Wheat bran 40 g/day results were not significantly different from wheat bran 20 g/day. Compared with placebo, consumption of olestra 20 g/day and 40 g/day for 6 days showed no significant difference in mean stool output (151 ± 18 g/day and 204 ± 28 g/day, respectively), mean BM frequency (1.8 ± 0.2 BM/day and 2.1 ± 0.3 BM/day, respectively), and stool water output (138 ± 13 g/day and 184 ± 31 g/day, respectively), a significant (p < 0.05) decrease in stool water content (75.5 ± 1.7% and 72.6 ± 2.2%, respectively), and either no effect on stool apparent viscosity (olestra 20 g/day, mean log PF, 3.0 ± 0.1 g) or a gradual stool-softening effect beginning study day 6 (olestra 40 g/day, log PF, 2.7 ± 0.1 g). None of the treatment groups showed a significant increase in GI symptoms compared with placebo.CONCLUSIONS:Consumption of wheat bran in excess of levels in a typical Western diet significantly increased stool output, but did not soften normal-viscosity stool nor result in an increase in common GI symptoms. The observed plateau effect for wheat bran at 40 g/day suggests a maximal mechanical stimulatory effect. Consumption of olestra in excess of usual snacking conditions did not result in a significant increase in stool output or common GI symptoms. At the highest level tested, olestra resulted in a gradual stool-softening effect after several days of consumption.
Constipation is a highly prevalent and difficult‐to‐cure health problem, forcing 10–20% of the worldwide population to seek medical care. Efficacy of treatments varies greatly among individuals, and problems are becoming more frequent despite higher consumption of fibre‐rich foods, the most popular solution for preventing such gastrointestinal disorders. The evidence that consumption of fibre prevents and relieves constipation is unconvincing or uncertain. The food industry has made great efforts to develop fibre‐rich ingredients, especially those from food by‐products and wastes. Except for psyllium and wheat bran, most of these ingredients have intermediate or low laxative potential and their efficacy needs to be confirmed by more clinical studies. This review suggests that there are major discrepancies between the proposed fibre‐enriched ingredients and the consumers' needs. As a lasting solution to prevent constipation, the true impact of dietary fibre and potent food‐grade laxatives might also be limited by overeating.
Digestive complaints are common in medicine, yet no systematic review of normal laxation has been published. Even definitions for digestive problems such as constipation and diarrhea vary greatly and tend to be subjective. Over-the-counter medicines for digestive disorders are commonly prescribed and consumed. However, the success of these treatments is poorly studied because standard protocols to determine "normal laxation" do not exist. With respect to laxation, in addition to food intake, stool size is affected by many factors, including sex, exercise, age, stress, bowel habits, psychological factors, medications, and many health conditions and diseases. In this article, we describe normal stool, review the methods used to determine healthy digestion and the factors that affect stool composition, and support the need for fecal collection and analyses in nutrition and gastroenterology studies
Sugar-free or reduced-sugar foods and beverages are very popular in the United States and other countries, and the sweeteners that make them possible are among the most conspicuous ingredients in the food supply. Extensive scientific research has demonstrated the safety of the 5 low-calorie sweeteners currently approved for use in foods in the United States–acesulfame K, aspartame, neotame, saccharin, and sucralose. A controversial animal cancer study of aspartame conducted using unusual methodology is currently being reviewed by regulatory authorities in several countries. No other issues about the safety of these 5 sweeteners remain unresolved at the present time. Three other low-calorie sweeteners currently used in some other countries–alitame, cyclamate, and steviol glycosides–are not approved as food ingredients in the United States. Steviol glycosides may be sold as a dietary supplement, but marketing this product as a food ingredient in the United States is illegal. A variety of polyols (sugar alcohols) and other bulk sweeteners are also accepted for use in the United States. The only significant health issue pertaining to polyols, most of which are incompletely digested, is the potential for gastrointestinal discomfort with excessive use. The availability of a variety of safe sweeteners is of benefit to consumers because it enables food manufacturers to formulate a variety of good-tasting sweet foods and beverages that are safe for the teeth and lower in calorie content than sugar-sweetened foods.
The present study sought to determine if alterations in the chemical nature and form of fat in food would reduce digestibility
while maintaining acceptability in rats. Oil-in-water emulsions (d<1μm) were prepared with either liquid palm oil, solid hydrogenated palm oil or solid docosane, all stabilized with sodium
caseinate. The emulsions were incorporated into a fat-free rodent feed, and each offered over 5days to separate cohorts of
12 male Sprague–Dawley rats housed in metabolic cages. The feed formulated with solid hydrogenated palm oil was significantly
less acceptable than the feeds containing either liquid palm oil or docosane (feed intake 4.9, 26.6 and 32.1g/animal/day
respectively). The proportion of the fat retained (i.e. absorbed) was significantly less in the animals consuming the feed
formulated with solid docosane than in the animals consuming either the liquid or solid palm oil (retention 8.7, 99.6, and
97.2%, respectively). The appearance of the feces from the rats fed docosane was different from the rats fed the triacylglycerol
samples and thermal analysis revealed many of the solid alkane droplets had not coalesced during passage through the rat’s
digestive system. These results indicate that indigestible fats can be packaged into food in a manner that does not compromise
the acceptability of the product, and does not produce any apparent intestinal distress.
KeywordsFats and oils–Fat substitutes–Emulsions/colloids–Fat crystallization
The aim of this study was to compare the effects of two nondigested, nonabsorbed dietary components on objective and subjective measures of gastrointestinal (GI) function.
A placebo-controlled parallel study compared the effects of wheat bran (20 g/day or 40 g/day in cereal), a well-known dietary fiber, with those of olestra (20 g or 40 g/day in potato chips), a nonabsorbed fat, on stool output, stool apparent viscosity (log peak force for extrusion [PF]), stool water content, and GI symptoms. Sixty subjects resided on a metabolic ward for 9 days: 3 days baseline and 6 days treatment.
Compared with placebo, consumption of 20 g/day wheat bran for 6 days resulted in a rapid (within 38 h) increase in mean (+/-SE) stool output (placebo, 150 +/- 29 g/day; bran, 246 +/- 35 g/day, p < 0.05), a directional increase in mean stool water content (placebo, 81.2 +/- 0.8%; bran, 83.9 +/- 0.8%), stool water output (placebo, 159 +/- 54 g/day; bran, 238 +/- 30 g/day), and bowel movement frequency (BM/day) (placebo, 2.2 +/- 0.4; bran, 2.6 +/- 0.4), and no stool-softening effect (placebo log PF, 2.9 +/- 0.1 g; bran log PF, 2.9 +/- 0.1 g). Wheat bran 40 g/day results were not significantly different from wheat bran 20 g/day. Compared with placebo, consumption of olestra 20 g/day and 40 g/day for 6 days showed no significant difference in mean stool output (151 +/- 18 g/day and 204 +/- 28 g/day, respectively), mean BM frequency (1.8 +/- 0.2 BM/day and 2.1 +/- 0.3 BM/day, respectively), and stool water output (138 +/- 13 g/day and 184 +/- 31 g/day, respectively), a significant (p < 0.05) decrease in stool water content (75.5 +/- 1.7% and 72.6 +/- 2.2%, respectively), and either no effect on stool apparent viscosity (olestra 20 g/day, mean log PF, 3.0 +/- 0.1 g) or a gradual stool-softening effect beginning study day 6 (olestra 40 g/day, log PF, 2.7 +/- 0.1 g). None of the treatment groups showed a significant increase in GI symptoms compared with placebo.
Consumption of wheat bran in excess of levels in a typical Western diet significantly increased stool output, but did not soften normal-viscosity stool nor result in an increase in common GI symptoms. The observed plateau effect for wheat bran at 40 g/day suggests a maximal mechanical stimulatory effect. Consumption of olestra in excess of usual snacking conditions did not result in a significant increase in stool output or common GI symptoms. At the highest level tested, olestra resulted in a gradual stool-softening effect after several days of consumption.
Market introduction of savory snacks containing olestra offered an opportunity to evaluate the safety of olestra in a free-living population and thereby compare the outcome to the previously established safety profile determined in clinical trials in which subjects were required to eat predetermined amounts at prescribed intervals. Therefore, a multifaceted postmarketing surveillance program was designed to evaluate consumer experience and safety of olestra in the marketplace. Customer comments were solicited through toll-free telephone numbers. Collected data were evaluated by both internal and external medical experts. About 10% of toll-free telephone calls reported health effects, most of which were gastrointestinal (GI) in nature. Clinical studies were designed and conducted to determine potential GI effects under the range of consumption patterns reported by toll-free calls. Health effects reported were those found commonly in the general population and analyses of the data found no biological reason to conclude that serious or meaningful health effects were the result of olestra consumption.
To report a case of significant additive gastrointestinal effects with concomitant use of orlistat and an olestra-containing snack food.
A 16-year-old African American girl with type 2 diabetes, hypercholesterolemia, and hypertension was participating in a pilot study that tested the safety and efficacy of orlistat. After 2 weeks of orlistat treatment, the patient presented to the clinic with complaints of soft, fatty/oily stools, flatus with discharge, abdominal pain, increased flatus, and fecal incontinence. On further questioning, it was determined that she was also consuming approximately 5 ounces of olestra-containing potato chips on a daily basis. The patient eliminated olestra from her diet and returned to the clinic with substantially diminished gastrointestinal adverse effects, despite continuing to take orlistat.
This is the first published case describing additive gastrointestinal effects after concurrent use of orlistat and olestra. Education about the potential for serious additive gastrointestinal adverse effects is important to prevent premature and unnecessary discontinuation of orlistat therapy. Awareness of this potential interaction could be especially important for patients with underlying disease states in which severe gastrointestinal symptoms could result in significant complications.
This case illustrates that significant gastrointestinal distress may result after olestra consumption during orlistat therapy. All patients receiving orlistat for the management of obesity should be properly educated about this potential drug-food interaction.
Olestra is a fat substitute made from fatty acids esterified to sucrose and can be used in the preparation of virtually any food made with fat. Foods made with olestra retain the mouthfeel, palatability and satiating effects of their full-fat counterparts without providing any digestible energy. Because olestra provides no energy, it has the potential to be a useful tool in weight loss and weight maintenance. Short-term studies of olestra replacement in foods demonstrate that fat replacement leads to a net reduction in fat intake. When excess total energy is available, fat replacement also reduces total energy intake in lean and obese men and women. In longer-term studies in which olestra is incorporated into the daily diet, there is an incomplete compensation for the fat energy replaced by olestra. When overweight men consumed olestra as part of a varied diet over nine months, weight loss continued for the duration of the study, whereas individuals receiving a typical low-fat diet regained most of the initial weight lost. Other studies are underway to examine the usefulness of olestra in long-term weight maintenance following weight loss. Post-marketing surveillance of olestra foods in the United States indicates that substitution of olestra for only 1-2 g of fat d-1 may be sufficient to prevent the average weight gain reported in adults of 0.5-1.0 kg year-1.
The 1996 Food and Drug Administration approval of the fat substitute olestra (sucrose polyester) called for active postmarketing surveillance because preapproval studies showed that olestra may lower circulating concentrations of fat-soluble nutrients such as vitamins and carotenoids.
The objective of the Olestra Post-Marketing Surveillance Study was to examine whether customary consumption of olestra-containing savory snacks was associated with changes in serum fat-soluble vitamin and carotenoid concentrations among free-living persons in geographically and ethnically distinct US cities.
Adults (n = 2535) and their children aged 12-17 y (n = 272) in Baltimore, Minneapolis, and San Diego attended clinic visits during which data were collected on diet, savory snack consumption, lifestyle, and anthropometric indexes. Blood samples were drawn to assay carotenoids and vitamins A, D, E, and K. Data and blood samples were collected both before and after the nationwide introduction of olestra. General estimating equations were used in multivariate-adjusted models that examined olestra's association with the specified serum nutrients.
Compared with no intake, the top 2 tertiles of olestra use in adults were associated with circulating carotenoid concentrations that were modestly but significantly lower (4.3% to 22.4%). There were no significant associations of olestra with any serum nutrients among adolescents.
This active postmarketing surveillance study of a food additive suggests that small decreases in serum fat-soluble nutrients are attributable to olestra use. Although health outcomes were not measured here, it is unlikely that these small changes in nutrient measures would adversely affect health.
Many drugs have been known to cause diarrhea, although their mechanism of action has not been well described. The gastrointestinal tract may become dysregulated when exposed to a drug that could disrupt mechanisms controlling mucosal permeability, transport, motility, and gut metabolism. This review examines the mechanism by which drugs induce diarrhea within the broad classification of watery, inflammatory, and fatty characteristics of the stool. Treatment may vary depending on this classification and usually includes withdrawal of the offending drug. However, in some cases, diarrhea may resolve with continued use or through nonspecific agents, such as Lomotil (Pfizer, New York, NY) or loperamide.
Our objective was to obtain national data of the estimated prevalence, sociodemographic relationships, and health impact of persons with functional gastrointestinal disorders. We surveyed a stratified probability random sample of U.S householders selected from a data base of a national market firm (National Family Opinion, Inc.). Questions were asked about bowel symptoms, sociodemographic associations, work absenteeism, and physician visits. The sampling frame was constructed to be demographically similar to the U.S. householder population based on geographic region, age of householder, population density, household income and household size. Of 8250 mailings, 5430 were returned suitable for analysis (66% response). The survey assessed the prevalence of 20 functional gastrointestinal syndromes based on fulfillment of multinational diagnostic (Rome) criteria. Additional variables studied included: demographic status, work absenteeism, health care use, employment status, family income, geographic area of residence, population density, and number of persons in household. For this sample, 69% reported having at least one of 20 functional gastrointestinal syndromes in the previous three months. The symptoms were attributed to four major anatomic regions: esophageal (42%), gastroduodenal (26%), bowel (44%), and anorectal (26%), with considerable overlap. Females reported greater frequencies of globus, functional dysphagia, irritable bowel syndrome, functional constipation, functional abdominal pain, functional biliary pain and dyschezia; males reported greater frequencies of aerophagia and functional bloating. Symptom reporting, except for incontinence, declines with age, and low income is associated with greater symptom reporting. The rate of work/school absenteeism and physician visits is increased for those having a functional gastrointestinal disorder. Furthermore, the greatest rates are associated with those having gross fecal incontinence and certain more painful functional gastrointestinal disorders such as chronic abdominal pain, biliary pain, functional dyspepsia and IBS. Preliminary information on the prevalence, socio-demographic features and health impact is provided for persons who fulfill diagnostic criteria for functional gastrointestinal disorders.
1. To evaluate the effect of age, sex and level of intake on the colonic response to wheat fibre, thirty healthy volunteers aged 17–62 years (nineteen men, eleven women) recruited from a local industry, were divided into four groups and given a controlled diet for two 3-week periods. The diet contained white bread during one period or one of four different amounts of bran-enriched wholemeal bread during the other (30, 60, 110, 170 g/d).
2. Wide variation was observed between subjects in stool weight on the basal diet and in response to wheat fibre. Stepwise regression analysis showed that the variation in stool weight was significantly related to sex ( t 4.0, P <0.001) but not to age, height, weight or energy:fibre intakes on the basal diet. Stool weight in men (162(SE 11) g/d) was approximately double that in women (83(SE 11) g/d). Transit time and stool weight were closely related and the effect of sex on stool weight could be explained entirely by differences in transit.
4. Faecal carbohydrate excretion increased with the addition of bran mainly due to increased amounts of cellulose and pentose (arabinose+xylose), whilst digestibility of dietary non-starch polysaccharide fell from 77.6 (SE 2.3)% on the white bread diet to 65.6 (SE 2.4)% with the added bran (t 7.4, P < 0.01, n26).
5. Faecal pH was more acid in men than in women and was related to methane production. Methane producers had higher faecal pH than non-producers (7.06 (SE 0.1 1) v. 6.65 (SE O.1)), lower stool weight (g/d; 93 (SE 12) v. 156 (SE 13)) and slower transit times (h; 84.6 (SE 11.7) v. 48.6 (SE 6.6)).
6. These studies show that, when on similar diets, women have much lower stool weights and slower transit times than men. Furthermore, within the range of amounts of wheat fibre used in this and other published work, stool weight increases in linear proportion to the dose of fibre added to the diet. Methane excretion in breath is associated in this group of subjects with slow transit time and high faecal pH.
The motor activity of the transverse, descending, and sigmoid colon was recorded for 24 hours in 14 healthy volunteers with a colonoscope positioned catheter. During the study the patients ate two 1000 kcal mixed meals and one continental breakfast. Colonic motor activity was low before meals and minimal during sleep; the motility index increased significantly after meals and at morning awakening. Most of the motor activity was represented by low amplitude contractions present singly or in bursts, which showed no recognisable pattern. All but two subjects also showed isolated high amplitude (up to 200 mmHg) contractions that propagated peristaltically over long distances at approximately 1 cm/sec. Most of these contractions occurred after morning awakening, and some in the late postprandial period, with a mean of 4.4/subject/24 h. The peristaltic contractions were often felt as an urge to defecate or preceded defecation, and could represent the manometric equivalent of the mass movements.
To investigate the mechanisms for elicitation of peristaltic activity in the human colon, we studied the effect of balloon distension of the transverse, descending, and sigmoid colon and the rectum. Fifteen healthy subjects were studied by means of a colonoscopically positioned probe carrying a 5-cm latex balloon. After positioning of the probe, stepwise distension was performed for each colonic segment (transverse, descending, sigmoid, rectum), and the onset of large (> 50 mm Hg) and small (< 50 mm Hg) propagated waves was observed. Analysis of the tracings showed: (1) In 8/15 subjects (53.3%), balloon distension elicited propagated contractions, but these contractions were qualitatively different from the spontaneously occurring high-amplitude propagated contractions previously found to occur in association with defecation. Therefore, intraluminal distension is probably not the cause of defecation-associated high-amplitude propagated contractions. (2) Pain reports were poorly correlated with propagated contractions elicited by balloon distension, suggesting that these contractions are not the cause of the pain produced by balloon distension. (3) The transverse colon shows lower pressures, fewer pain reports, and fewer large propagated contractions in response to balloon distension as compared to the descending and the sigmoid colon.
Our objective was to obtain national data of the estimated prevalence, sociodemographic relationships, and health impact of persons with functional gastrointestinal disorders. We surveyed a stratified probability random sample of U.S. householders selected from a data base of a national market firm (National Family Opinion, Inc.). Questions were asked about bowel symptoms, sociodemographic associations, work absenteeism, and physician visits. The sampling frame was constructed to be demographically similar to the U.S. householder population based on geographic region, age of householder, population density, household income, and household size. Of 8250 mailings, 5430 were returned suitable for analysis (66% response). The survey assessed the prevalence of 20 functional gastrointestinal syndromes based on fulfillment of multinational diagnostic (Rome) criteria. Additional variables studied included: demographic status, work absenteeism, health care use, employment status, family income, geographic area of residence, population density, and number of persons in household. For this sample, 69% reported having at least one of 20 functional gastrointestinal syndromes in the previous three months. The symptoms were attributed to four major anatomic regions: esophageal (42%), gastroduodenal (26%), bowel (44%), and anorectal (26%), with considerable overlap. Females reported greater frequencies of globus, functional dysphagia, irritable bowel syndrome, functional constipation, functional abdominal pain, functional biliary pain and dyschezia; males reported greater frequencies of aerophagia and functional bloating. Symptom reporting, except for incontinence, declines with age, and low income is associated with greater symptom reporting. The rate of work/school absenteeism and physician visits is increased for those having a functional gastrointestinal disorder. Furthermore, the greatest rates are associated with those having gross fecal incontinence and certain more painful functional gastrointestinal disorders such as chronic abdominal pain, biliary pain, functional dyspepsia and IBS. Preliminary information on the prevalence, socio-demographic features and health impact is provided for persons who fulfill diagnostic criteria for functional gastrointestinal disorders.
A manometric method was developed to study the motor activity in the unprepared human colon, and the results in eight healthy subjects were compared with those obtained in the same subjects after bowel cleansing with a non-absorbable solution containing polyethylene glycol 4000 (PEG). A tube assembly (4.5 m long, 12 lumen) was introduced through the nose and passed through the gastrointestinal tract. Two manometric recordings were performed one month apart, one without any preparation and the other after bowel cleansing with PEG. There was no obvious qualitative difference between the recordings performed in the uncleansed and PEG cleansed colon. Moreover, in the unprepared colon motility indices were close to those measured in the cleansed colon. The number of high amplitude propagated contractions (mean (SEM)) was, however, higher in the cleansed colon (8.6 (2.8) v 5.4 (1.8)/subject/9 h in the unprepared colon; p < 0.04). It is concluded that in healthy subjects taking a regular diet, motor activity is not different between the uncleansed and cleansed colon with PEG, except for the high amplitude propagated contractions, which occur more frequently in the cleansed colon.
Olestra, a nonabsorbable, energy-free fat substitute used in snack foods, has been anecdotally reported to cause gastrointestinal (GI) adverse events, although such effects were not expected based on results from randomized trials, in which it was consumed in typical snack patterns.
To determine whether ad libitum consumption of potato chips made with the fat substitute olestra results in a different level of GI symptoms than regular chips made with triglyceride (TG).
Randomized, double-blind, parallel, placebo-controlled trial.
A suburban Chicago, III, multiplex cinema.
A total of 1123 volunteers aged 13 to 88 years.
Subjects were given a beverage and an unlabeled, white 369-g (13-oz) bag of potato chips made with olestra or TG during a free movie screening.
Total and specific GI symptoms reported during a telephone interview conducted from 40 hours to 10 days after ingestion; level of potato chip consumption; and satiety level.
Of 563 evaluable subjects in the olestra chip group, 89 (15.8%) reported 1 or more GI symptoms, while 93 (17.6%) of the 529 evaluable subjects in the regular TG chip group did so (difference in symptom frequency between olestra and TG, -1.8; 95% confidence interval, -6.2 to 2.7; P=.47). For specific GI symptoms (eg, gas, diarrhea, abdominal cramping), there were no significant differences between olestra and TG chips. Fewer olestra chips were consumed than TG chips (60 vs 77 g [2.1 vs 2.7 oz]; P<.001), with olestra chips receiving lower taste scores (5.6 vs 6.4 on a 9-point scale; P<.001). Consumption levels did not correlate with the rate of symptom reporting in either the olestra or TG group. There was no difference in satiety scores between olestra and TG chips (5.7 vs 5.9 on a 9-point scale; P=.07).
This study demonstrates that ad libitum consumption of olestra potato chips during 1 sitting is not associated with increased incidence or severity of GI symptoms, nor does the amount consumed predict who will report GI effects after short-term consumption of either olestra or TG potato chips.
Background: Olestra is a nonabsorbable, energy-free fat substitute. Because it is not absorbed, it may cause digestive symptoms when consumed in large amounts. Objective: To compare the frequency and impact of gastrointestinal symptoms in adults and children who freely consume snacks containing olestra or regular snacks in the home. Design: 6-week, double-blind, randomized, parallel, placebo-controlled trial. Setting: General community. Participants: 3181 volunteers 2 to 89 years of age. Intervention: Households received identical packages labeled as containing olestra corn or potato chips. These packages contained either olestra or regular chips (control). Measurement: Gastrointestinal symptoms and their impact on daily activities were reported in a daily record. Results: At least one gastrointestinal symptom was reported by 619 of 1620 (38.2%) persons in the olestra group and 576 of 1561 (36.9%) controls (difference, 1.3 percentage points [95% CI, -3.6 to 6.2 percentage points]; P = 0.60). In general, the groups did not differ significantly in the proportion of participants who reported individual gastrointestinal symptoms; however, more controls reported nausea (8.4% compared with 5.7%; difference, -2.7 percentage points [Cl, -4.9 to -0.4 percentage points]; P = 0.02). The only difference between groups for the mean numbers of days on which symptoms were reported was that participants in the olestra group had 1 more symptom-day of more frequent bowel movements than did controls (3.7 symptom-days compared with 2.8 symptom days; difference, 0.9 symptom-days [Cl, 0.1 to 1.8 symptom-days]; P = 0.04). The groups did not differ in the impact of symptoms on daily activities. Conclusions: Clinically meaningful or bothersome gastrointestinal effects are not associated with unregulated consumption of olestra corn and potato chips in the home.
Context.— Olestra, a nonabsorbable, energy-free fat substitute used in snack foods,
has been anecdotally reported to cause gastrointestinal (GI) adverse events,
although such effects were not expected based on results from randomized trials,
in which it was consumed in typical snack patterns.Objective.— To determine whether ad libitum consumption of potato chips made with
the fat substitute olestra results in a different level of GI symptoms than
regular chips made with triglyceride (TG).Design.— Randomized, double-blind, parallel, placebo-controlled trial.Setting.— A suburban Chicago, Ill, multiplex cinema.Subjects.— A total of 1123 volunteers aged 13 to 88 years.Intervention.— Subjects were given a beverage and an unlabeled, white 369-g (13-oz)
bag of potato chips made with olestra or TG during a free movie screening.Main Outcome Measures.— Total and specific GI symptoms reported during a telephone interview
conducted from 40 hours to 10 days after ingestion; level of potato chip consumption;
and satiety level.Results.— Of 563 evaluable subjects in the olestra chip group, 89 (15.8%) reported
1 or more GI symptoms, while 93 (17.6%) of the 529 evaluable subjects in the
regular TG chip group did so (difference in symptom frequency between olestra
and TG, −1.8; 95% confidence interval, −6.2 to 2.7; P=.47). For specific GI symptoms (eg, gas, diarrhea, abdominal cramping),
there were no significant differences between olestra and TG chips. Fewer
olestra chips were consumed than TG chips (60 vs 77 g [2.1 vs 2.7 oz]; P<.001), with olestra chips receiving lower taste scores
(5.6 vs 6.4 on a 9-point scale; P <.001). Consumption
levels did not correlate with the rate of symptom reporting in either the
olestra or TG group. There was no difference in satiety scores between olestra
and TG chips (5.7 vs 5.9 on a 9-point scale; P =.07).Conclusions.— This study demonstrates that ad libitum consumption of olestra potato
chips during 1 sitting is not associated with increased incidence or severity
of GI symptoms, nor does the amount consumed predict who will report GI effects
after short-term consumption of either olestra or TG potato chips.
OBJECTIVE:The aim of this study was to compare the effects of two nondigested, nonabsorbed dietary components on objective and subjective measures of gastrointestinal (GI) function.METHODS:A placebo-controlled parallel study compared the effects of wheat bran (20 g/day or 40 g/day in cereal), a well-known dietary fiber, with those of olestra (20 g or 40 g/day in potato chips), a nonabsorbed fat, on stool output, stool apparent viscosity (log peak force for extrusion [PF]), stool water content, and GI symptoms. Sixty subjects resided on a metabolic ward for 9 days: 3 days baseline and 6 days treatment.RESULTS:Compared with placebo, consumption of 20 g/day wheat bran for 6 days resulted in a rapid (within 38 h) increase in mean (±SE) stool output (placebo, 150 ± 29 g/day; bran, 246 ± 35 g/day, p < 0.05), a directional increase in mean stool water content (placebo, 81.2 ± 0.8%; bran, 83.9 ± 0.8%), stool water output (placebo, 159 ± 54 g/day; bran, 238 ± 30 g/day), and bowel movement frequency (BM/day) (placebo, 2.2 ± 0.4; bran, 2.6 ± 0.4), and no stool-softening effect (placebo log PF, 2.9 ± 0.1 g; bran log PF, 2.9 ± 0.1 g). Wheat bran 40 g/day results were not significantly different from wheat bran 20 g/day. Compared with placebo, consumption of olestra 20 g/day and 40 g/day for 6 days showed no significant difference in mean stool output (151 ± 18 g/day and 204 ± 28 g/day, respectively), mean BM frequency (1.8 ± 0.2 BM/day and 2.1 ± 0.3 BM/day, respectively), and stool water output (138 ± 13 g/day and 184 ± 31 g/day, respectively), a significant (p < 0.05) decrease in stool water content (75.5 ± 1.7% and 72.6 ± 2.2%, respectively), and either no effect on stool apparent viscosity (olestra 20 g/day, mean log PF, 3.0 ± 0.1 g) or a gradual stool-softening effect beginning study day 6 (olestra 40 g/day, log PF, 2.7 ± 0.1 g). None of the treatment groups showed a significant increase in GI symptoms compared with placebo.CONCLUSIONS:Consumption of wheat bran in excess of levels in a typical Western diet significantly increased stool output, but did not soften normal-viscosity stool nor result in an increase in common GI symptoms. The observed plateau effect for wheat bran at 40 g/day suggests a maximal mechanical stimulatory effect. Consumption of olestra in excess of usual snacking conditions did not result in a significant increase in stool output or common GI symptoms. At the highest level tested, olestra resulted in a gradual stool-softening effect after several days of consumption.
"Bockus" has so long been synonymous with gastroenterology that it is good once again to see a new edition of this classic textbook, now split into a projected four volumes. Physicians can now buy and read the first volume covering disorders of the esophagus and stomach as well as a general approach to the patient and his examination. The other three volumes are in preparation.Harry Bockus has wisely recognized that a four-volume text is beyond even his stalwart control and capacity, and so five of his former associates serve in a pentarchy as associate editors. He has also turned over many chapters to world-famous experts so that "Bockus" now represents the opinions of a multitude of experts rather than the preferences and prejudices of one of the most experienced clinicians of modern gastroenterology.There are some disappointing omissions. For example, it is hard to find very much on the
Abdominal symptoms due to motility disturbances of the lower gut consist mainly of discrete pain episodes or a long-lasting feeling of fullness and distension. Long-term recording has shown that these symptoms are partly related to propagated contraction waves of the colon which induce mass movement of colonic contents. Patients probably experience that normal contractile activity is unpleasant or painful and apparently have a decreased threshold of perception. Also, peculiar contraction patterns of the small intestine ('clustered contractions') have been related to pain episodes. Fullness and distension are characteristic for slow transit constipation, but also occur in disordered defecation. Future studies on treatment will have to concentrate on pathophysiologically defined subgroups.
(C) Lippincott-Raven Publishers.
We wished to determine if visceral perception in the rectum and stomach is altered in patients with irritable bowel syndrome and to evaluate the effects on visceral sensation of 5-HT3 receptor blockade. Twelve community patients with diarrhea-predominant irritable bowel syndrome and 10 healthy controls were studied in a double-blind, randomized, placebo-controlled study. Using two barostats, the stomach and rectum were distended, with pressure increments of 4 mm Hg, from 10 to 26 mm Hg; visceral perception was measured on an ordinal scale of 0–10. Personality traits were measured using standard psychological methods, and somatic pain was evaluated by immersion of the nondominant hand in cold water. The effect of 5-HT3 antagonism was tested with a single intravenous dose of ondansetron at 0.15 mg/kg. Gastric perception was higher in irritable bowel syndrome, but rectal distension was perceived similarly in irritable bowel syndrome and controls. Pain tolerance to cold water was also similar in irritable bowel syndrome and controls. Ondansetron induced rectal relaxation and increased rectal compliance but did not significantly alter gastric compliance or visceral perception. Psychological test scores were similar in patients and controls. We conclude that in this group of psychologically normal patients with irritable bowel syndrome, who were not chronic health-care seekers, visceral perception was normal. Ondansetron did not alter gut perception in health or in irritable bowel syndrome.
Information concerning bowel habits was gathered from a representative sample of 14,407 United States adults in the first National Health and Nutrition Examination Survey in 1971–1975 and approximately 10 years later among the same individuals. The prevalence of self-reported constipation, diarrhea, infrequent defecation (three or fewer bowel movements per week), and frequent defecation (two or more bowel movements per day) increased with aging. Women were more likely than men (P0.05) to report constipation (20.8% compared to 8.0%) and infrequent defecation (9.1% compared to 3.2%). Blacks were more likely than whites to report infrequent defecation (P0.05). Older respondents reporting constipation were more likely to use laxatives or stool softeners than younger respondents reporting constipation, but they were also less likely to have infrequent defecation. To evaluate factors predictive of impaired bowel function, case definitions were created using information concerning complaint of constipation, laxative use, frequency of defecation, and stool consistency. Female gender, black race, fewer years of education, low physical activity, and symptoms of depression were independent risk factors for impaired bowel function. This study provides national estimates of bowel complaints and their natural history and examines possible risk factors for constipation.
The techniques commonly used to evaluate the transit of contents through the gut feature some limitations for being either inaccurate, invasive, inconvenient, or potentially dangerous for the subjects. Aim of this study was to establish a safe, noninvasive and accurate technique for the measurement of segmental oroanal transit time. We localized an orally ingested magnetic marker by means of a biomagnetic instrumentation that allows us to identify in a three-dimensional pattern the position of a biomagnetic source inside the body. The biomagnetic localizations were compared with the anatomical data obtained by magnetic resonance imaging investigations. The study was performed in 12 healthy subjects, and scans were taken every hour up to the arrival of the marker into the cecum; thereafter, scans were taken every 4 hr up to the elimination of the marker. In 99% of the isofield maps obtained from each field scan, the marker was localized within the bowel walls. The mean oroanal transit time was 565 hr, the mouth-to-cecum transit time was 131.7 hr, and the total colonic transit time was 43.55 hr (meansem). Segmental colon transit did not show major differences among the regions considered, although most of the time was spent in the right colon. In fact, a good correlation was found between transit time through the right colon and oroanal and total colonic transit (r=0.77,Pr=0.79,P
Three enteropathogenic Escherichia coli (E.P.E.C.) strains (O127:K63:H6, O128:K67:H2, and O142:K86:H6) isolated from outbreaks of infantile diarrhoea and one strain from the "normal" colonic flora (E. coli HS) of a healthy adult were fed in doses of 10(6), 10(8), and 10(10) organisms in NaHCO3 to adult volunteers. The strains, which had been stored for 7--9 years, gave negative results in sensitive tests for heat-labile (L.T.) enterotoxin (Y-1 adrenal-cell test), heat-stable (S.T.) enterotoxin (infant mouse assay), invasiveness (guineapig eye test), and gross fluid accumulation (infant rabbit assay). Two strains (O142 and O127) caused diarrhoea. L.T. or S.T. enterotoxins were not found in E. coli stool isolates from individuals with diarrhoea and no one had a rise in L.T. antitoxin titre; the findings suggest that L.T. and S.T. enterotoxins were not involved in pathogenesis of the diarrhoea. Non-invasive E.P.E.C. strains probably induce diarrhoea by a mechanism (presumably an enterotoxin) distinct from L.T. or S.T. enterotoxins.
A washout technic with intestinal infusion of an inert gas mixture was used to study the relation of gas to functional abdominal symptoms. The volume of gas in the intestinal tract (176 plus or minus 28 ml S.E.M.) of 12 fasting patients with chronic complaints of excess gas did not differ significantly (P greater than 0.10) from that of 10 controls (199 plus or minus 31 ml). Similarly, there was no difference in the composition or accumulation rate of intestinal gas. However, more gas tended to reflux back into the stomach in patients who complained of abdominal pain during infusion of volumes of gas well tolerated by controls. Six patients with severe pain during the study had intestinal transit times of gas (40 plus or minus 6 minutes S.E.M.) that were significantly (P less than 0.05) longer than those of the control group (22 plus or minus 3 minutes). Thus, complaints of bloating, pain and gas may result from disordered intestinal motility in combination with an abnormal pain response to gut distention rather than from increased volumes of gas.
Low fecal weight and slow bowel transit time are thought to be associated with bowel cancer risk, but few published data defining bowel habits in different communities exist. Therefore, data on stool weight were collected from 20 populations in 12 countries to define this risk more accurately, and the relationship between stool weight and dietary intake of nonstarch polysaccharides (NSP) (dietary fiber) was quantified. In 220 healthy U.K. adults undertaking careful fecal collections, median daily stool weight was 106 g/day (men, 104 g/day; women, 99 g/day; P = 0.02) and whole-gut transit time was 60 hours (men, 55 hours; women, 72 hours; P = 0.05); 17% of women, but only 1% of men, passed < 50 g stool/day. Data from other populations of the world show average stool weight to vary from 72 to 470 g/day and to be inversely related to colon cancer risk (r = -0.78). Meta-analysis of 11 studies in which daily fecal weight was measured accurately in 26 groups of people (n = 206) on controlled diets of known NSP content shows a significant correlation between fiber intake and mean daily stool weight (r = 0.84). Stool weight in many Westernized populations is low (80-120 g/day), and this is associated with increased colon cancer risk. Fecal output is increased by dietary NSP. Diets characterized by high NSP intake (approximately 18 g/day) are associated with stool weights of 150 g/day and should reduce the risk of bowel cancer.
The techniques commonly used to evaluate the transit of contents through the gut feature some limitations for being either inaccurate, invasive, inconvenient, or potentially dangerous for the subjects. Aim of this study was to establish a safe, noninvasive and accurate technique for the measurement of segmental oroanal transit time. We localized an orally ingested magnetic marker by means of a biomagnetic instrumentation that allows us to identify in a three-dimensional pattern the position of a biomagnetic source inside the body. The biomagnetic localizations were compared with the anatomical data obtained by magnetic resonance imaging investigations. The study was performed in 12 healthy subjects, and scans were taken every hour up to the arrival of the marker into the cecum; thereafter, scans were taken every 4 hr up to the elimination of the marker. In 99% of the isofield maps obtained from each field scan, the marker was localized within the bowel walls. The mean oroanal transit time was 56 +/- 5 hr, the mouth-to-cecum transit time was 13 +/- 1.7 hr, and the total colonic transit time was 43.5 +/- 5 hr (mean +/- SEM). Segmental colon transit did not show major differences among the regions considered, although most of the time was spent in the right colon. In fact, a good correlation was found between transit time through the right colon and oroanal and total colonic transit (r = 0.77, P < 0.02, r = 0.79, P < 0.02 respectively). In conclusion, this method might be a safe alternative to the techniques presently used in the clinical setting for the measurement of intestinal transit.
The prevalence of chronic gastrointestinal symptoms and the irritable bowel syndrome (IBS) in the elderly, and their impact on health, is largely unknown. The prevalence of symptoms compatible with IBS was estimated in a representative sample of elderly community residents, and the impact of these symptoms was determined on presentation for health care. An age- and sex-stratified random sample of noninstitutionalized Olmsted County, Minnesota, residents aged 65-93 years were mailed a valid questionnaire; 77% responded (n = 328). The age- and sex-adjusted prevalence (per 100 persons) of frequent abdominal pain was 24.3 [95% confidence interval (CI), 19.3-29.2]. Chronic constipation and chronic diarrhea had prevalences of 24.1 (95% CI, 19.1-29.0) and 14.2 (95% CI, 10.1-18.2), respectively. Fecal incontinence more than once a week was reported in 3.7 per 100 (95% CI, 1.6-5.9). The prevalence of symptoms compatible with IBS (greater than or equal to 3 Manning criteria with frequent abdominal pain) was 10.9 per 100 (95% CI, 7.2-14.6). Among the subjects sampled who had abdominal pain, chronic constipation, and/or chronic diarrhea (n = 152), only 23% had seen a physician for pain or disturbed defecation in the prior year, and this behavior was poorly explained by the symptoms. It is concluded that complaints consistent with functional gastrointestinal disorders are common in the elderly, but symptoms are a poor predictor of presentation for medical care.
This study monitored high-amplitude propagated contractions (HAPCs) in ambulating subjects over a 24-h period using a new ambulatory recording system. Twelve healthy volunteers aged 34 +/- 5.96 yr participated. Approximately 12 h after a Colyte bowel prep, a small catheter (OD less than 3 mm), containing three solid-state pressure transducers spaced 5 cm apart, was positioned by flexible sigmoidoscope at 40-50 cm from the anal verge. A battery-operated data recorder sampled the pressure at each port at 1 Hz and stored the values on all ports if any port exceeded 75 mmHg. At the conclusion of the 24-h period, an X-ray was taken to confirm the location of the catheter. Fifty-four percent of all HAPCs preceded a bowel movement by less than or equal to 1 h. Forty-nine percent of all HAPCs occurred within 1 h after a high-fat meal, and 33% occurred within 1 h of morning awakening. Reverse propagated waves, not previously described in the colon, were observed in three individuals. Spontaneous high-amplitude caudally propagated contractions occur 6.9 +/- 1.5 times/24 h in the sigmoid colon in ambulating asymptomatic individuals and are temporally related to defecation and meals. Peristaltic activity is decreased during sleep. This recording technique was reliable and well tolerated in all participants.
We studied the dose response to soft white winter wheat fiber on fecal output in a group of healthy volunteers whose breakfasts consisted of wheat fiber cereals in amounts that provided 0.3 g, 5.6 g, 9.5 g, 11.2 g, 19.0 g, and 28.4 g dietary fiber per day for 14 days; no other aspects of their diet were altered. A linear dose response was observed between the six levels of fiber intake (r = 0.983, p less than 0.01) with a 1-g increase in wheat fiber, producing a mean 2.7-g increase in fecal weight. This increase was independent of the initial daily fecal weight of the volunteer (mean 117 +/- 64 g/day, range 5-297 g/day, n = 73). The maximum increase in fecal output due to cereal fiber was reached after the first week on the supplement. These data support the use of graded amounts of cereal fiber in the management of constipation.
The motor activity of colonic segments proximal to the rectosigmoid junction are poorly understood. We investigated colonic peristalsis (high-amplitude propagated contractions; HAPCs) in 20 healthy volunteers by means of a colonoscopically positioned manometric probe and low-compliance infusion system. In all, 110 HAPCs were recorded from the ascending, transverse, descending, and sigmoid colon, and their features and daily distribution were analyzed and characterized. Mean frequency was 6.1 +/- 0.9 (SE) per subject per 24 h, mean amplitude was 110.37 +/- 6.3 mmHg, mean duration was 14.15 +/- 0.8 s, and mean propagation velocity was 1.11 +/- 0.1 cm/s. There were no significant differences among colonic segments. Diurnal changes of HAPCs were also noted, with a maximum frequency after meals and after awakening in the morning, and a minimum recorded in the late afternoon and during the night. These HAPCs may represent the manometric equivalent of mass movements.
Intestinal reflexes induced by distention in dogs are facilitated by either simultaneous or previous distentions. The aim of this study was to determine whether these phenomena also modulate the responses to intestinal distention, particularly perception, in humans.
Perception and intestinal relaxation were measured in 11 healthy subjects in response to increasing jejunal balloon distentions tested (by stimulus-response trials) alone, as control, and with conditioning distentions applied either simultaneously, immediately (10 seconds) before at the same site, or immediately before and 5 cm distant. In 8 additional subjects, the effect of prolonged (90-minute) conditioning distention was tested.
Conditioning had more pronounced effects on perception than on intestinal reflexes. Perception of intestinal distention increased (by 84 +/- 47%; P < 0.05) when a simultaneous distention was applied nearby. By contrast, perception decreased (by 38 +/- 12%; P < 0.05) when a previous distention was applied at the same but not at an adjacent site. Prolonged intestinal distention elicited remarkably stable perception during a 90-minute period. The effects of conditioning were unrelated to intestinal compliance because it remained unchanged.
In humans, temporospatial interactions of gut stimuli activate modulatory phenomena that determine the perception intensity of the stimuli.
The colon exhibits three types of contractions: individual phasic (short and long duration), organized groups (MMCs and nonmigrating motor complexes), and ultrapropulsive (giant migrating contractions). The individual phasic contractions and the MMCs and nonmigrating motor complexes produce extensive mixing and kneading of fecal material and slow net distal propulsion. The GMCs produce mass movements and expel feces during defecation. All contractions are controlled by myogenic, neural, and chemical mechanisms. The myogenic mechanisms determine the timing and frequency of contractions and the duration and distance of propagation of contractions. The neurochemical mechanisms determine whether the contractions will occur at a given site.
Up to 60% of patients with IBS have lowered perception thresholds in the rectum to balloon distension. The current study sought to test the hypothesis that IBS patients with normal perception thresholds in the rectum show hypersensitivity of afferent pathways in the sigmoid colon. Eleven healthy normal subjects and eight IBS patients with normal rectal perception thresholds underwent a balloon distension protocol in the sigmoid and rectum. Discomfort thresholds, receptive relaxation, compliance, and referral patterns were measured. Although IBS patients had significantly lower discomfort thresholds in the sigmoid when measured as volume, pressure, and wall tension, thresholds were similar to normals. Receptive relaxation and dynamic compliance were significantly decreased in IBS patients in the sigmoid. Referral patterns were similar during sigmoid distention in IBS patients in comparison to normals. Despite normal perception thresholds in rectum and sigmoid, IBS patients show evidence for alterations in rectosigmoid afferent mechanisms. In the sigmoid, this is seen in the form of reduced reflex relaxation and compliance and in the rectum in the form of altered viscerosomatic referral.
Potential chronic (14-d average) and acute (single-day) estimated daily intakes (EDI) were computed for olestra, a fat replacement intended for use in preparing savory snacks. The EDI were computed from eating occasions reported during a 14-d Menu Census survey among 4741 consumers; values were increased by 10% for conservatism. The eating occasions included all meals and in-between meal occasions eaten at home or away. Data from only those individuals who ate savory snacks at least once during the 14 d were used; this included 3820 individuals (81% of the sample) and represented a total of 16,067 eating days (24% frequency). The estimated mean chronic intake ranged from 1.8 to 4.7 g/d, depending on age and gender; at the 90th percentile, the range was 4.1-11.0 g/d. For all ages and both genders, the estimated mean intake was 3.1 g/d. Estimated acute intakes at the mean and 90th percentile ranged from 5.5 to 16.5 g/d and from 10.2 to 24.0 g/d, respectively, depending on age and gender. For all ages and both genders, the estimated mean intake was 10.2 g/d. The lack of parity in the chronic and acute intake estimates indicates that savory snacks are not eaten on a daily basis by the majority of snack eaters. The survey data were analyzed to understand the potential temporal eating patterns of olestra from savory snacks. When snacks were consumed, on average, 69% of the eating occasions were with main meals and 31% were between meals. Savory snacks did not contribute a major fraction of total food to the diet; only 7 and 18% of main meals contained a savory snack food at the 50th and 90th percentile, respectively. For the 50th-percentile consumer (all ages, both genders), savory snacks were eaten four times during the 14-d survey period, and the eating occasions occurred on 3 d. Comparable results for 90th-percentile consumers were 10 eating occasions and 8 eating days.
The aim of this study was to determine how bulk fibers and calcium docusate affect regional dehydration and digesta viscosity throughout the large intestine. Fifty-two pigs were fed a chow diet supplemented with a bulk laxative, placebo, or calcium docusate for three days, after which the pigs were sacrificed and the contents of the large bowel were analyzed. Digesta occurred as a continuum from liquid (cecum, 91.2% water content) to solid (rectum, 70.5% water content). The observed 20.7% difference in water content resulted in a 240-fold increase in viscosity. Half of this water is reabsorbed in the first 18% of the large bowel length where viscosity remains relatively low. Compared to placebo, calcium docusate and calcium polycarbophil had no significant effect on digesta water content or viscosity, polycarbophil exhibited significantly (P < 0.05) lower digesta viscosity in three bowel segments, and psyllium exhibited significantly (P < 0.01) lower viscosity in six bowel segments and higher water content in nine bowel segments. In conclusion, the majority of digesta dehydration occurs early in the proximal large bowel, while the greatest increases in viscosity occur in the distal bowel. Relatively small decreases in digesta water content result in large increases in digesta viscosity. Psyllium, and to a lesser extent polycarbophil, are able to resist dehydration, resulting in a softer digesta.
The aim of this study was to characterize propagating contractions in the unprepared colon of freely ambulating mini pigs. A telemetric method was used to record colonic motility continuously for six consecutive days in a 40-cm segment of proximal colon. Propagating contractions occurred over a wide range of propagation rates (0.4-16.7 cm/sec), peak amplitudes (10-116 mm Hg) and pressure wave durations (5.3-40.0 sec). Propagating contractions were divided into two groups by duration and wave-form: short-duration symmetrical and long-duration asymmetrical. Short-duration (7.8 +/- 0.9 sec) symmetrical wave-from propagating contractions exhibited a higher frequency (27.9 +/- 2.6 events/day), more rapid propagation rate (3-16.7 cm/sec; mean +/- SEM: 4.9 +/- 1.7 cm/sec), and a lower peak amplitude (31.2 +/- 0.9 mm Hg) compared to long-duration (19.2 +/- 5.1 sec) asymmetrical propagating contractions, which were less frequent (6.1 +/- 0.7 events/day), slower in propagation rate (0.4-2 cm/sec; mean +/- SEM: 1.5 +/- 0.7 cm/sec), and higher in peak amplitude (51.6 +/- 2.4 mm Hg). The results show that propagating contractions occur over a wide spectrum, from short-duration, low-amplitude, rapidly propagating contractions to long-duration, high-amplitude, slowly propagating contractions.
Olestra is a nonabsorbable, energy-free fat substitute. Because it is not absorbed, it may cause digestive symptoms when consumed in large amounts.
To compare the frequency and impact of gastrointestinal symptoms in adults and children who freely consume snacks containing olestra or regular snacks in the home.
6-week, double-blind, randomized, parallel, placebo-controlled trial.
General community.
3181 volunteers 2 to 89 years of age.
Households received identical packages labeled as containing olestra corn or potato chips. These packages contained either olestra or regular chips (control).
Gastrointestinal symptoms and their impact on daily activities were reported in a daily record.
At least one gastrointestinal symptom was reported by 619 of 1620 (38.2%) persons in the olestra group and 576 of 1561 (36.9%) controls (difference, 1.3 percentage points [95% CI, -3.6 to 6.2 percentage points]; P = 0.60). In general, the groups did not differ significantly in the proportion of participants who reported individual gastrointestinal symptoms; however, more controls reported nausea (8.4% compared with 5.7%; difference, -2.7 percentage points [CI, -4.9 to -0.4 percentage points]; P = 0.02). The only difference between groups for the mean numbers of days on which symptoms were reported was that participants in the olestra group had 1 more symptom-day of more frequent bowel movements than did controls (3.7 symptom-days compared with 2.8 symptom days; difference, 0.9 symptom-days [CI, 0.1 to 1.8 symptom-days]; P = 0.04). The groups did not differ in the impact of symptoms on daily activities.
Clinically meaningful or bothersome gastrointestinal effects are not associated with unregulated consumption of olestra corn and potato chips in the home.
The goal of this study was to compare the stool-softening effects of olestra and wheat bran and to determine if changes in patterns of propagating colonic motility were associated with the observed stool softening. Mini-pigs were fed chow (control) or chow supplemented with olestra (80 g/day) or wheat bran (80 g/day) for four days. Proximal colonic motility was monitored continuously, stool viscosity and fecal output measured daily, and cecal-to-anal transit time determined. Compared to controls, olestra and wheat bran significantly softened stool but had no effect on fecal wet weight or colonic transit time. Neither olestra nor wheat bran changed the number of propagating contractions per day, amplitude, motility index, propagation velocity, or the relative distribution of fast and slow propagating contractions. Our data suggest that the stool-softening effects of olestra and wheat bran are not due to direct stimulation of propagating contractions in the colon of the mini-pig.
The Functional Gastroin-testinal Disorders, Diagnosis, Physiology and Treatment
- D Drossman
- J Richter
- N Talley
- W Thompson
- E Corazziari
- W Whitehead
Drossman, D., Richter, J., Talley, N., Thompson, W., Corazziari, E., and Whitehead, W. (Eds.) (1994). The Functional Gastroin-testinal Disorders, Diagnosis, Physiology and Treatment, 1st ed.
Clinical Gastroenterology
- H M Spiro
Spiro, H. M. (Ed.) (1993). Clinical Gastroenterology, 4th ed., p.
355. McGraw-Hill, New York, NY.
Part III, Department of Health and Human Services, Food and Drug Administration, 21 CFR Part 172
Federal Register, Part III, Department of Health and Human
Services, Food and Drug Administration, 21 CFR Part 172, January 30, 1996.