Content uploaded by Leonardo Marzio
Author content
All content in this area was uploaded by Leonardo Marzio on Mar 13, 2019
Content may be subject to copyright.
Digestive and Liver Disease 39 (2007) 530–536
Alimentary Tract
Peppermint oil (Mintoil®) in the treatment of irritable bowel syndrome:
A prospective double blind placebo-controlled randomized trial
G. Cappello a, M. Spezzaferro a, L. Grossi a, L. Manzoli b, L. Marzio a,∗
aSection of Digestive Sciences, Department of Medicine, G.d’Annunzio University, Chieti-Pescara, Italy
bSection of Epidemiology and Public Heath, G.d’Annunzio University, Chieti-Pescara, Italy
Received 26 September 2006; accepted 12 February 2007
Available online 8 April 2007
Abstract
Introduction. The use of peppermint oil in treating the irritable bowel syndrome has been studied with variable results probably due to the
presence of patients affected by small intestinal bacterial overgrowth, lactose intolerance or celiac disease that may have symptoms similar to
irritable bowel syndrome.
Aim. The aim of the study was to test the effectiveness of enteric-coated peppermint oil in patients with irritable bowel syndrome in whom
small intestinal bacterial overgrowth, lactose intolerance and celiac disease were excluded.
Methods. Fifty-seven patients with irritable bowel syndrome according to the Rome II criteria, with normal lactose and lactulose breath
tests and negative antibody screening for celiac disease, were treated with peppermint oil (two enteric-coated capsules twice per day or placebo)
for 4 weeks in a double blind study. The symptoms were assessed before therapy (T0), after the first 4 weeks of therapy (T4) and 4 weeks after
the end of therapy (T8). The symptoms evaluated were: abdominal bloating, abdominal pain or discomfort, diarrhoea, constipation, feeling
of incomplete evacuation, pain at defecation, passage of gas or mucus and urgency at defecation. For each symptom intensity and frequency
from 0 to 4 were scored. The total irritable bowel syndrome symptoms score was also calculated as the mean value of the sum of the average
of the intensity and frequency scores of each symptom.
Results. At T4, 75% of the patients in the peppermint oil group showed a >50% reduction of basal (T0) total irritable bowel syndrome
symptoms score compared with 38% in the placebo group (P< 0.009). With peppermint oil at T4and at T8compared with T0a statistically
significant reduction of the total irritable bowel syndrome symptoms score was found (T0: 2.19 ±0.13, T4: 1.07 ±0.10*, T8: 1.60 ±0.10*,
*P< 0.01 compared with T0, mean ±S.E.M.), while no change was found with the placebo.
Conclusion. A 4 weeks treatment with peppermint oil improves abdominal symptoms in patients with irritable bowel syndrome.
© 2007 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.
Keywords: Double blind trial; Irritable bowel syndrome; Peppermint oil; Placebo
1. Introduction and aim
The symptoms of the irritable bowel syndrome (IBS) are
represented by recurrent episodes of abdominal distension
and bloating, abdominal pain and altered bowel habits with
constipation, diarrhoea and urgency to defecate [1]. These
symptoms, however, do not exclusively characterize this dis-
∗Corresponding author at: Fisiopatologia Digestiva, Ospedale Civile
Pescara, Via Fonte Romana 8, Pescara 65124, Italy. Tel.: +39 085 425 2692;
fax: +39 085 4295 547.
E-mail address: marzio@unich.it (L. Marzio).
ease and may be found with similar intensity and frequency
in patients with lactose intolerance (LI), syndrome of small
intestinal bacterial overgrowth (SIBO) and celiac disease
(CD) [2,3]. SIBO and LI are associated with increased gas
production, which may sometimes trigger abdominal discom-
fort and bloating which are also considered also the cardinal
symptoms in IBS [4,5]. Furthermore, a high prevalence of
celiac disease has been observed in patients with bloating and
diarrhoea and positive H2-lactose breath test. In these patients
the symptoms related to lactase deficiency seem to be the
only manifestation of celiac disease [6]. Basing themselves
on these data, some authors suggest that these diseases should
1590-8658/$30 © 2007 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.dld.2007.02.006
G. Cappello et al. / Digestive and Liver Disease 39 (2007) 530–536 531
be previously excluded in clinic therapeutic trials with inves-
tigational drugs that affect IBS [7]. Peppermint oil has been
tested in children [8] and adults [9] with IBS, with conflicting
results. A recent meta-analysis on this topic concluded that
the role of peppermint oil has not yet been established beyond
a reasonable doubt [10]. Among the various possibilities of
applying this therapy, the potential inclusion of patients with
the above-cited diseases should be taken into account.
The aim of the study was, therefore, to test the effec-
tiveness of pH-dependent, enteric-coated, peppermint oil in
patients with symptoms indicative of IBS in whom SIBO, LI
and CD have been excluded.
2. Materials and methods
Patients with symptoms indicative of IBS that met the
Rome II criteria [11] were investigated. All patients had a
negative lactose breath test for lactose intolerance (a positive
test required an increase in breath hydrogen >20 ppm within
90 or 180 min after an oral ingestion of <20 g lactose pow-
der diluted in 150 ml tap water) and a lactulose breath test
for bacterial overgrowth (a positive test required two distinct
peaks >20 ppm of breath hydrogen within 90 min after 6 g
lactulose diluted in 150 ml tap water). Both tests were per-
formed during the month preceding the study. A stool test
for ova and/or parasites, occult stool blood, blood test for
full count, liver function tests, tissue transglutaminase and
anti-endomysium antibodies for CD had to be in the nor-
mal range. Abdominal ultrasound and total colonoscopy were
performed when required by clinical symptoms. The exclu-
sion criteria were: age under 18 and over 80 years, previous
surgery on the abdomen except appendectomy, inflammatory
bowel disease, colonic diverticular disease, intestinal neopla-
sia, systemic disease, thyroid disease and chronic assumption
of medication that could interfere with intestinal motility,
secretion and sensation.
The study was approved by the ethical committee of
G.d’Annunzio University.
2.1. Protocol
The study was a randomized, double blind, placebo-
controlled study. Peppermint oil and a placebo were prepared
in enteric-coated, gastro-protected capsules which do not dis-
solve during their passage through the stomach and which
only dissolve when there is intestinal pH of 7.0 or higher.Each
capsule was filled with 225 mg of peppermint oil and 45 mg of
Natrasorb, a particular starch that absorbs oils in solid powder
(Mintoil®Cadigroup, Rome, Italy), while the placebo con-
tained 225 mg of maltodextrin with mint flavour (Cadigroup,
Rome, Italy). Each patient admitted to the study was ran-
domly given two capsules of peppermint oil or placebo twice
a day, for 4 weeks, on the basis of data from a computer-
generated list. The capsules were administered 1 h before
meals in order to guarantee low gastric pH which prevents an
untimely capsule dissolution with the release of peppermint
oil into the stomach.
The symptoms score data were collected by two
researchers (G.C. and M.S.), following an intensity and
frequency scale from 0 to 4 – intensity: 0 = absent,
1 = mild, 2 = moderate, 3 = severe, 4 = unbearable; frequency:
0 = absent, 1 = once per month, 2 = once per week, 3 = twice
per week, 4 = > three times per week. Symptoms were made
note of at the beginning of the trial, at the end of the trial (4
weeks later) and 4 weeks after the end of the trial. The symp-
toms evaluated were the following: abdominal bloating or
distension, abdominal pain or discomfort, diarrhoea (>3 defe-
cation/day, constipation (<3 stools/week), pain at evacuation,
urgency of bowel movement, sense of incomplete evacuation
and passage of gas or mucus.A total IBS symptoms score
was also calculated as follows: (a) a mean score for each
symptom was obtained for each patient adding the relative
intensity and frequency scores and halving this value; (b) the
mean scores of the eight symptoms were summed for each
patient and divided by 8, obtaining a total IBS mean score
for every patient. The collection of symptoms was performed
at entry (T0), at the end of treatment (T4) and 4 weeks after
the end of treatment (T8). Remission of IBS symptoms was
defined as a >50% improvement of the overall IBS symptoms
score from baseline T0to T4and T8.
2.2. Statistical analysis
The sample size was calculated assuming a mean differ-
ence between groups on the basis of the total change of the
total IBS symptoms score before and after the treatment of
1.0 or greater points (with a standard deviation = 1.0), which
was considered a clinically relevant difference. With α= 0.05,
β= 0.80 and considering a 10% value of withdrawals and
dropouts, a minimum number of 25 patients was therefore
required in each group.
Two sets of populations were identified for the purpose of
assessing the effectiveness, namely, the “intention to treat”
(ITT) group and “per protocol” (PP) group. The χ2-test was
used to compare the percentage of patients with remission
of the IBS symptoms in the group of peppermint oil versus
that of the placebo. The Student’s t-test for paired data was
used to test the changes in the symptoms score between T0
and T4and T8within the group with peppermint oil and
within the group with the placebo. The Mann–Whitney U-
test (two-tailed) was used to compare the symptoms score
between peppermint oil and the placebo at T0,T
4and T8.A
P-value ≤0.05 was considered statistically significant. Data
are presented as mean ±S.E.M.
3. Results
3.1. Characteristics at baseline
Fifty-seven patients, who satisfied the inclusion criteria,
were studied: 28 taking peppermint oil and 29 taking a
532 G. Cappello et al. / Digestive and Liver Disease 39 (2007) 530–536
Table 1
Distribution of IBS symptoms among patients with IBS taking peppermint oil or placebo.
Total patients Peppermint oil (No. 24) (%) Placebo (No. 26) (%) P*
Abdominal pain or discomfort 24 100 26 100 n.s.
Bloating or distension 22 92 24 89 n.s.
Diarrhoea 18 75 20 74 n.s.
Constipation 6 25 6 26 n.s.
Feeling of incomplete evacuation 12 50 16 59 n.s.
Urgency 12 50 16 59 n.s.
Pain at evacuation 12 50 10 38 n.s.
Pass of gas or mucus 14 58 15 60 n.s.
*χ2-test.
placebo. At T8, 4 weeks after the completion of the treat-
ment period, three patients in the peppermint oil group
and three patients in the placebo group did not return for
the final control examination. These patients were excluded
from the study. One patient in the peppermint group with-
drew due to intense heartburn after taking the medication.
The data from fifty patients, therefore, were available for
comparison. Twenty-four patients were in the peppermint
oil group (18 women, 6 men; mean age 42, range 22–58)
and 26 patients (20 women and 6 men; mean age 40,
range 20–60) in the placebo group. The two groups were
balanced regarding smokers/non-smokers and the consump-
tion of alcohol (72% of patients in the peppermint oil and
75% in the placebo group did not smoke, and 83% and
88%, respectively, drank less than 15 g of ethyl alcohol
per day). The two groups were well balanced regard-
ing the baseline symptoms in terms of the percentage of
patients with the presence or absence of a specific symptom
(Table 1) and basal symptoms score (Fig. 1).
3.2. Response to treatment
At the end of the 4 weeks of treatment (T4) and of the sub-
sequent 4 weeks (T8), a statistically significant higher number
of patients in the peppermint oil group had a ≥50% reduc-
tion in the mean total IBS symptoms score versus the placebo
group at both ITT and PP analyses (Table 2).
The variation of the total IBS symptoms score computed
at T0,T
4and T8is described in Fig. 1. It may be observed
that in the group treated with peppermint oil there was a
statistically significant improvement in total IBS symptoms
score (P< 0.01) at T4, with a persisting beneficial effect at
T8(P< 0.05) too. In the placebo group there was a reduc-
Fig. 1. Total IBS symptoms score (mean±S.E.M.) before (T0), after 4
weeks of treatment (T4) with peppermint oil (Pe) or placebo (Pl) and after 4
weeks of wash out (T8). (*) P< 0.05 vs. T0(t-test); ()P< 0.05 vs. placebo
(Mann–Whitney U-test).
tion in the total IBS symptoms score at T4(P< 0.05) with
a return falling within the baseline values at T8(Fig. 1). In
the peppermint oil group all the symptoms evaluated were
significantly reduced at T4and at T8, while in the placebo
group, diarrhoea, pain and bloating improved significantly at
T4(Fig. 2).
The Mann–Whitney U-test used to compare the pepper-
mint oil group with the placebo group, showed a statistically
significant lower total IBS symptoms score in the pepper-
mint oil group in comparison with that of the placebo at T4
and T8(Fig. 1). The same test also showed that the score of
each symptom evaluated was significantly lower at T4in the
peppermint oil group in comparison with the placebo group
(Fig. 2).
Table 2
Number of patients with ≥50% reduction of total IBS symptoms score at T4and T8
PP P*ITT P*
Peppermint oil Placebo Peppermint oil Placebo
T475%(18/24) 38% (10/26) 9 64%(18/28) 34% (10/29) 2
T854%(13/24) 11% (3/26) 1 46%(13/28) 10% (3/29) 2
*χ2-test.
G. Cappello et al. / Digestive and Liver Disease 39 (2007) 530–536 533
Fig. 2. Mean value between intensity and frequency of IBS symptoms (mean ±S.E.M.) before (T0), after 4 weeks of treatment (T4) with peppermint oil (Pe)
or placebo (Pl) and after 4 weeks of wash out (T8). (*) P< 0.05 vs. T0(t-test); ()P<0.05 vs. placebo (Mann–Whitney U-test).
534 G. Cappello et al. / Digestive and Liver Disease 39 (2007) 530–536
4. Discussion
This study shows that, in patients with IBS, treatment with
enteric-coated capsules of peppermint oil given twice a day
for 4 weeks is more effective than placebo in reducing abdom-
inal symptoms related to IBS than a placebo. The beneficial
effect of peppermint oil also lasts for 1 month after the therapy
in more than 50% of treated patients.
Several types of therapy are available for IBS treatment
and include bulking agents, prokinetics, antispasmodics, 5-
HT agonists and antagonists, smooth muscle relaxants and
antidepressants. However, most studies are hampered by poor
methodology and inconclusive findings [12]. Furthermore,
complementary and alternative medical therapies and prac-
tices such as hypnotherapy, forms of herbal therapy and
certain probiotics are widely employed in the treatment of
IBS. The absence of truly randomized placebo-controlled
trials for many of these therapies has limited meaningful
progress in this area [13].
So far, few studies have shown a beneficial effect of pep-
permint oil on symptoms of IBS both in adults and in children.
A critical review and meta-analysis published in the Amer-
ican Journal of Gastroenterology [10] analysed five double
blind, placebo-controlled trials. Two trials did not demon-
strate significant differences between peppermint oil versus
placebo in patients with IBS [14,15], while the other three
found a significant difference [16–18]. Several methodolog-
ical limitations were identified and the conclusion of these
authors was that, despite the apparently positive results of
the published trials, the role of peppermint oil in the treat-
ment of IBS was far from being established. Since then, two
more trials have been published on this topic: one in chil-
dren and the other in adults. In the first trial in the adult
population from Taiwan [9] some relief in the severity of
symptoms was recorded in 79% of the patients treated with
peppermint oil with significant differences from the placebo
group. In the second study on children [8] affected by IBS
a general improvement in the symptoms was found in 76%
of the patients treated with peppermint oil compared with
19% of those receiving the placebo. However, symptoms
such as abdominal distension and gas production remained
unchanged. The lack of the effectiveness of peppermint oil on
such symptoms found in this study may be explained by the
presence of patients affected by LI or SIBO that may account
for 5–50% of patients with IBS, according to recent studies
[19,20].
In our study the improvement in IBS symptoms observed
in the group treated with peppermint oil may be due to the
relaxing effect of peppermint on the intestinal smooth muscle
obtained by the interference of menthol with the movement
of calcium across the cell membrane [21]. Furthermore, the
antispasmodic effect of peppermint oil could explain both
the reduced diarrhoea present in the majority of our patients
through a prolongation of oro-caecal transit time [22] but also
of the constipation present in the rest of the group. In fact,
antispasmodics in fact may decrease the functional obstruc-
tion caused by increased phasic colonic contractions that may
be present in constipation [23].
Constipation and related symptoms including bloating,
abdominal distension, difficulty at evacuation, pain at evacu-
ation and the feeling of incomplete evacuation also improved
in our patients. Since these symptoms may be related to
abnormal intestinal gas production [24,25] an action on
enteric bacteria for peppermint oil may be suggested. Pep-
permint oil has an intrinsic antibacterial activity in vitro and
in vivo, and it has been shown that it is able to reduce the
intestinal hydrogen production in patients with bacterial over-
growth [26]. Its influence on the enteric flora presumably
persists beyond the therapeutic period, an effect that may
explain why the positive effect of peppermint oil on IBS
symptoms was still present in more than half of our patients
1 month after the end of therapy. Indeed, a similar effect
has been recorded in a recent study with probiotics in IBS
[27].
In this study the therapeutic trial lasted 4 weeks, which
is normally considered too short a period for the observation
of a condition such as IBS, which is, by definition, chronic
and intermittent. In the present study, however, the total IBS
symptoms score calculated at the end of the 4 weeks of treat-
ment with peppermint oil is strikingly reduced in comparison
with the placebo. This suggests that a longer period of ther-
apy is unlikely to produce a more positive response. On the
contrary, since after treatment the beneficial effect was lost
in about 50% of the patients, it may be also suggested that a
longer period of therapy may be required if an improvement
in symptoms is to be maintained.
The placebo effect in the present study is in the range
of all similar studies in IBS. It must be underlined that the
specific improvement that has been recorded with the placebo
on diarrhoea and bloating in our study may be due to the
intrinsic effect of maltodextrin, the principal component of
our placebo capsule that has been shown to be effective in
children with infectious diarrhoea [28].
Three patients in each group left their group during the
study due to reasons not linked to the treatment. One patient
in the peppermint oil group refused to continue the study due
to prolonged heartburn and a minty taste in his mouth. This
side-effect, already recorded in previous studies [8,17], may
be due to the incorrect assumption of the capsule (patient
chewing the capsule) or due to the capsule dissolving too
early into the stomach, causing oesophageal reflux of gastric
juice mixed with menthol.
In summary, this study shows that patients with IBS may
benefit from a 4-week treatment with enteric-coated pepper-
mint oil. The improvement in the symptoms lasts longer than
the therapeutic period in almost half of the treated patients.
These data suggest that when peppermint oil is administered
for a short 4-week period, it is safe and effective for patients
with IBS.
Further studies, however, with longer therapeutic periods
will be required before the definite impact of peppermint oil
therapy in IBS can be established.
G. Cappello et al. / Digestive and Liver Disease 39 (2007) 530–536 535
Practice points
•Consider that in IBS symptoms such as
abdominal discomfort or pain, bloating, con-
stipation or diarrhoea are present also in
lactose intolerance, small intestinal bacterial
overgrowth and celiac disease.
•Perform in every patients with a suggested
diagnosis of IBS a lactose, glucose or lactu-
lose breath test and dosage of the antibody
to tissue transglutaminase.
•Most of the available substances suggested
for the treatment of IBS is devoted towards
the reduction of a specific symptom such as
constipation, diarrhoea and bloating or pain,
and their therapeutic effect is limited to a
short period of time.
Research agenda
•The therapeutic choice for IBS includes bulk-
ing agents, prokinetics, antispasmodics, 5-HT
agonists and antagonists, smooth muscle
relaxants, antidepressants, hypnotherapy,
some forms of herbal extract and certain
probiotics. Controlled clinical trials with a
clear-cut evidence of a real efficacy of these
substances are few and most of them are
hampered by poor methodology and incon-
clusive findings.
•IBS may be due to altered intestinal
microflora, excessive intestinal smooth mus-
cle motility, reduced bowel wall compliance
and enhanced pain perception. The search of
a substance that may act on one or more of
these cited points may be beneficial in the
treatment of the disease.
Conflict of interest statement
None declared.
Acknowledgement
The authors thank Mrs. Catherine Hlywka for reviewing
the English style of the manuscript.
References
[1] Thompson WG, Longstreth GF, Drossman DA, Heaton KW, Irvine EJ,
M¨
uller-Lissner SA. Functional bowel disorders and functional abdom-
inal pain. Gut 1999;45(Suppl. 2):43–7.
[2] Frissora CL, Koch KL. Symptom overlap and comorbidity of irrita-
ble bowel syndrome with other conditions. Curr Gastroenterol Rep
2005;7:264–71.
[3] Lin HC. Small intestinal bacterial overgrowth: a framework for under-
standing irritable bowel syndrome. J Am Med Assoc 2004;292:
852–8.
[4] Pimentel M, Kong Y, Park S. Breath testing to evaluate lactose intol-
erance in irritable bowel syndrome correlates with lactulose testing
and may not reflect true lactose malabsorption. Am J Gastroenterol
2003;98:2700–4.
[5] Vernia P, Di Camillo M, Marinaro V. Lactose malabsorption, irrita-
ble bowel syndrome and self-reported milk intolerance. Dig Liver Dis
2001;33:234–9.
[6] Ojetti V, Nucera G, Migneco A, Gabrielli M, Lauritano C, Danese S, et
al. High prevalence of celiac disease in patients with lactose intolerance.
Digestion 2005;71:106–10.
[7] De Giorgio R, Barbara G, Stanghellini V, Cremon C, Salvioli B, De
Ponti F, et al. Diagnosis and therapy of irritable bowel syndrome.
Aliment Pharmacol Ther 2004;20(Suppl. 2):10–22.
[8] Kline RM, Kline JJ, Di Palma J, Barbero GJ. Enteric-coated, pH-
dependent peppermint oil capsules for the treatment of irritable bowel
syndrome in children. J Pediatr 2001;138:125–8.
[9] Liu JH, Chen GH, Yeh HZ, Huang CK, Poon SK. Enteric-coated
peppermint-oil capsules in the treatment of irritable bowel syn-
drome: a prospective, randomized trial. J Gastroenterol 1997;32:
765–8.
[10] Pittler MH, Ernst E. Peppermint oil for irritable bowel syndrome:
a critical review and metaanalysis. Am J Gastroenterol 1998;93:
1131–5.
[11] Ringel Y, Sperber AD, Drossman DA. Irritable bowel syndrome. Annu
Rev Med 2001;52:319–38.
[12] Lesbros-Pantoflickova D, Michetti P, Fried M, Beglinger C, Blum AL.
Meta-analysis: the treatment of irritable bowel syndrome. Aliment
Pharmacol Ther 2004;20:1253–69.
[13] Hussain Z, Quigley EM. Systematic review: complementary and alter-
native medicine in the irritable bowel syndrome. Aliment Pharmacol
Ther 2006;23:465–71.
[14] Nash P, Gould SR, Bernardo DE. Peppermint oil does not relieve the
pain of irritable bowel syndrome. Br J Clin Pract 1986;40:292–3.
[15] Carling I, Svedberg LE, Hulten S. Short term treatment of the irritable
bowel syndrome: a placebo-controlled trial of peppermint oil against
hyoschamine. OPMEAR 1989;34:55–7.
[16] Dew MJ, Evans BK, Rhodes J. Peppermint oil for the irritable bowel
syndrome: a multicentre trial. Br J Clin Pract 1984;38:394–8.
[17] Lech Y, Olesen KM, Hey H, Rask-Pedersen E, Vilien M, Ostergaard O.
Treatment of irritable bowel syndrome with peppermint oil. A double-
blind study with a placebo. Ugeskr Laeger 1988;150:2388–9.
[18] Rees WD, Evans BK, Rhodes J. Treating irritable bowel syndrome with
peppermint oil. Br Med J 1979;6194:835–6.
[19] Farup PG, Monsbakken KW, Vandvik PO. Lactose malabsorption in a
population with irritable bowel syndrome: prevalence and symptoms.
A case-control study. Scand J Gastroenterol 2004;39:645–9.
[20] Peralta S, Petta S, Venezia G, Bellia U, Camm`
a C, Crax`
ı A. Small
intestinal bacterial overgrowth: a new face of irritable bowel syndrome?
Dig Liver Dis 2006;38(Suppl. 1):S203.
[21] Hills JM, Aaronson PI. The mechanism of action of peppermint oil on
gastrointestinal smooth muscle. Gastroenterology 1991;101:55–65.
[22] Grigoleit HG, Grigoleit P. Gastrointestinal clinical pharmacology of
peppermint oil. Phytomedicine 2005;12:607–11.
[23] Snape Jr WJ. Role of colonic motility in guiding therapy in patients
with constipation. Dig Dis 1997;15:104–11.
[24] Nobaek S, Johansson ML, Molin G, Ahrne S, Jeppsson B. Alteration of
intestinal microflora is associated with reduction in abdominal bloating
and pain in patients with irritable bowel syndrome. Am J Gastroenterol
2000;95:1231–8.
[25] Pimentel M, Mayer AG, Park S, Chow EJ, Hasan A, Kong
Y. Methane production during lactulose breath test is associated
536 G. Cappello et al. / Digestive and Liver Disease 39 (2007) 530–536
with gastrointestinal disease presentation. Dig Dis Sci 2003;48:86–
92.
[26] Logan AC, Beaulne TM. The treatment of small intestinal bacterial
overgrowth with enteric-coated peppermint oil: a case report. Altern
Med Rev 2002;7:410–7.
[27] Whorwell PJ, Altringer L, Morel J, Bond Y, Charbonneau D, O’Mahony
L, et al. Efficacy of an encapsulated probiotic Bifidobacterium infantis
35624 in women with irritable bowel syndrome. Am J Gastroenterol
2006;101:1581–90.
[28] Santos Ocampo PD, Bravo LC, Rogacion JM, Battad GR. A randomized
double-blind clinical trial of a maltodextrin-containing oral rehydra-
tion solution in acute infantile diarrhea. J Pediatr Gastroenterol Nutr
1993;16:23–8.
