Constipation of anorectal outlet obstruction: Pathophysiology, evaluation and management

Tzaneio General Hospital of Piraeus, Le Pirée, Attica, Greece
Journal of Gastroenterology and Hepatology (Impact Factor: 3.63). 05/2006; 21(4):638-46. DOI: 10.1111/j.1440-1746.2006.04333.x
Source: PubMed

ABSTRACT Constipation is a subjective symptom of various pathological conditions. Incidence of constipation fluctuates from 2 to 30% in the general population. Approximately 50% of constipated patients referred to tertiary care centers have obstructed defecation constipation. Constipation of obstructed defecation may be due to mechanical causes or functional disorders of the anorectal region. Mechanical causes are related to morphological abnormalities of the anorectum (megarectum, rectal prolapse, rectocele, enterocele, neoplasms, stenosis). Functional disorders are associated with neurological disorders and dysfunction of the pelvic floor muscles or anorectal muscles (anismus, descending perineum syndrome, Hirschsprung's disease). However, this type of constipation should be differentiated by colonic slow transit constipation which, if coexists, should be managed to a second time. Assessment of patients with severe constipation includes a good history, physical examination and specialized investigations (colonic transit time, anorectal manometry, rectal balloon expulsion test, defecography, electromyography), which contribute to the diagnosis and the differential diagnosis of the cause of the obstructed defecation. Thereby, constipated patients can be given appropriate treatment for their problem, which may be conservative (bulk agents, high-fiber diet or laxatives), biofeedback training or surgery.

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    • "Failure of relaxation of the puborectalis and the external anal sphincter muscles, or paradoxical contraction of these muscles during straining to defecate is called anismus (Preston & Lennard-Jones 1985). The basic mechanism behind persistent constipation is the failure of the anorectal angle to straighten and the anal canal to shorten as a result of sustained contraction of the puborectalis muscle (Andromanakos et al. 2006). "
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    ABSTRACT: The aim of this study was to evaluate a rehabilitative programme including biofeedback training for the treatment of chronic constipation. A prospective series of patients with constipation, as defined by the Rome II diagnostic criteria, were assessed by a clinician, a dietitian and a physiotherapist. Anorectal physi- ology investigations and defecography were performed prior to and after the programme. The treatment involved consultation by the dietitian, postural re-education and pelvic floor re-education regarding the proper pattern of defecation. The subjects were followed up in alternate weeks for the first 3 months and then monthly for another 3 months. Twenty patients have been recruited into the programme since 2005. Ten subjects have completed the course of treatment and three have defaulted; the remaining seven were still undergoing treatment at the time of writing. On completion of the programme, there was a significant improvement in fibre intake (pre-treatment=12.9191.06 g; post-treatment= 20.2661.064 g; P=0.001), average straining effort (pre-treatment=6.360.391; post-treatment=3.720.391; P=0.001) and average straining time (pre- treatment=17.612.172 min; post-treatment=6.002.172 min; P=0.004). The subjects reported a >50% improvement in their symptoms. A rehabilitative programme for constipation can significantly ameliorate the problem of constipa- tion. The method of anorectal manometry was employed to assess the paradoxical response of the anorectum during attempted defecation.
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    ABSTRACT: Constipation is a common problem, which may be due to slow transit or faecal evacuation disorders. Though the screening test of colonic transit study using radio-opaque markers given at 0, 24 and 48 hours followed by abdominal X-ray at 72 hours is a good protocol in the West, it is not suitable for Indians who have a rapid gut transit. Nine patients with adult Hirschsprung disease, 11 with chronic intestinal pseudo-obstruction diagnosed using standard investigations and 11 healthy subjects were evaluated by colonic transit study using radio-opaque markers (SGmark), 20 each at O, 12 and 24 hours followed by an abdominal X-ray at 36 and 60 hours. The cut-off was determined by using receiver operating characteristic (ROC) curves, and sensitivity, specificity, positive and negative predictive values and diagnostic accuracy were determined. The total number of markers retained in the abdomen and those in the right segment at 36 hours in patients with Hirschsprung disease and chronic intestinal pseudo-obstruction was higher than that in healthy subjects though the number in the left and rectosigmoid segments were comparable. The abdominal X-ray at 60 hours, total number of markers and number in all segments were higher in patients with Hirschsprung disease and chronic intestinal pseudoobstruction than in healthy subjects. The best cut-off by ROC curves at 36 and 60 hours was 30 and 14 markers, respectively. The sensitivity, specificity, positive and negative predictive values, diagnostic accuracy and area under the ROC curve at 36 hours were 90%, 82%, 90%, 82%, 87% and 0.9, respectively; the corresponding values at 60 hours were 95%, 100%, 100%, 92%, 97% and 0.99, respectively. Using the proposed protocol, the colonic transit study is able to distinguish patients with specific motility disorders causing constipation such as Hirschsprung disease and chronic intestinal pseudo-obstruction from healthy subjects with reasonable sensitivity and specificity, and shows that an abdominal X-ray at 60 hours is better than one at 36 hours.
    The National medical journal of India 11/2006; 20(5):225-9. · 0.91 Impact Factor
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    ABSTRACT: Outlet dysfunction is responsible for 25% of all cases of chronic constipation. The aim of this article was to report our outcomes and investigate the efficacy of the different treatments that we have adopted to solve it. One hundred and twenty-six patients were treated with either surgery and/or biofeedback therapy. Ninety-seven of the 126 patients underwent surgery; 48 with hidden rectal prolapse: 44 underwent a stapled transanal rectal resection using a double stapler PPH-01 and 4 a single stapler PPH-01; 31 with rectocele and 18 with both hidden rectal prolapse and rectocele, respectively, underwent a stapled transanal rectal resection using a double stapler PPH-01. Thirteen of 97 patients showing outlet dysfunction in spite of surgery progressed to biofeedback therapy. 29 of the 126 patients were treated with biofeedback training only. Surgery helped 51.6% of treated for rectocele, 75% of those treated for hidden rectal prolapse, and 78% of patients treated for both rectocele and hidden rectal prolapse, respectively. Approximately 80% of patients treated with biofeedback alone and 67.8% of those treated with both surgery and biofeedback reported an improvement, respectively. Treatment of the outlet dysfunction can be difficult. The therapeutic option chosen for each subject in spite of a careful functional patient examination may not prove to be the most appropriate one. Our experience suggests that the surgery of the obstructed defecation could achieve better outcomes if a course of biofeedback therapy precedes it, above all in patients with both organic and functional disorders, and the repair of rectocele with stapled transanal rectal resection fails to resolve the outlet dysfunction in several cases.
    Chirurgia italiana 01/2008; 60(4):509-18.
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