Inaccuracy of patient-reported descriptions of and satisfaction with bowel actions in irritable bowel syndrome.

BACKGROUND: Perception of diarrhea and constipation differs greatly. This study aimed to correlate subjective and objective assessment of fecal characteristics in irritable bowel syndrome (IBS) patients. METHODS: Data from two interventional dietary trials with varying FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols) or gluten content were interrogated. Subjects rated their dissatisfaction with stool consistency daily using a visual analog scale during the interventions. Subjects collected stools at the end of each intervention. Each stool was scored according to the King's Stool Chart (KSC). Fecal water content (FWC) was measured on pooled feces by freeze drying, with diarrhea defined as ≥78%. KEY RESULTS: Seventy IBS (Rome III) and eight healthy subjects were studied. Each subject's self-rating of stool consistency during the most symptomatic diet was approximately double that of their least. Degree of dissatisfaction with stool consistency correlated poorly with changes in FWC and KSC. IBS subtype related poorly to objective measures of stool consistency. Sixty percent of IBS-D subjects had diarrhea on objective measures. Eighty-five percent with IBS-C had hard and formed stools but three patients met the criteria for diarrhea. One healthy subject had diarrhea on FWC and KSC, and six had hard, formed stools. No differences in FWC was observed when subjects consumed differing amounts of FODMAPs or gluten (all P > .200). CONCLUSIONS AND INFERENCES: There are major disparities between patients' stool descriptions and objective features of constipation and diarrhea. Patient-reported bowel habits require more interrogation for accurate IBS subtyping. Varying FODMAP or gluten content of the diet is not associated with consistent change in FWC.

Review article: dyssynergic defaecation and biofeedback therapy in the pathophysiology and management of functional constipation.

BACKGROUND: Functional constipation is a common clinical presentation in primary care. Functional defaecation disorders are defined as the paradoxical contraction or inadequate relaxation of the pelvic floor muscles during attempted defaecation (dyssynergic defaecation) and/or inadequate propulsive forces during attempted defaecation. Prompt diagnosis and management of dyssynergic defaecation is hindered by uncertainty regarding nomenclature, diagnostic criteria, pathophysiology and efficacy of management options such as biofeedback therapy. AIM: To review the evidence pertaining to the pathophysiology of functional defaecation disorders and the efficacy of biofeedback therapy in the management of patients with dyssynergic defaecation and functional constipation. METHODS: Relevant articles addressing functional defaecation disorders and the efficacy of biofeedback therapy in the management of dyssynergic defaecation and functional constipation were identified from a search of Pubmed, MEDLINE Ovid and the Cochrane Library. RESULTS: The prevalence of dyssynergic defaecation in patients investigated for chronic constipation is as many as 40%. Randomised controlled trials have demonstrated major symptom improvement in 70%-80% of patients undergoing biofeedback therapy for chronic constipation resistant to standard medical therapy and have determined it to be superior to polyethylene glycol laxatives, diazepam or sham therapy. Long-term studies have shown 55%-82% of patients maintain symptom improvement. CONCLUSIONS: Dyssynergic defaecation is a common clinical condition in patients with chronic constipation not responding to conservative management. Biofeedback therapy appears to be a safe, successful treatment with sustained results for patients with dyssynergic defaecation. Further studies are required to standardise the diagnosis of dyssynergic defaecation in addition to employing systematic protocols for biofeedback therapy.

Pathophysiology of fecal incontinence differs between men and women: a case-matched study in 200 patients.

BACKGROUND: Fecal incontinence (FI) is a common and socially disabling condition with obstetric trauma considered the principal etiological factor. This study aimed to systematically evaluate symptom presentation and anorectal function in both females and males with FI. METHODS: One hundred males (M) and 100 age-matched females (F) with FI presenting between 2012 and 2014 were identified from a prospectively collected database. Comparison of clinical (history, symptom profile, and severity using validated questionnaires) and anorectal physiological (manometry, rectal sensory testing, endoanal ultrasonography, and evacuation proctography) data between M and F was performed. KEY RESULTS: Incidence of prior anal surgery (M: 28% vs F: 18%, p = 0.13) and abdominal surgery (M: 25% vs F: 26%, p = 0.90) was similar between sexes, but females had a higher incidence of previous pelvic surgery (M: 4% vs F: 47%, p < 0.001). Eighty-five females were parous and 75% reported history of traumatic vaginal delivery. There was a trend toward higher St Mark's incontinence scores in females (mean ± SD; M: 13 ± 4 vs F: 14 ± 5, p = 0.06). In men, structural sphincter abnormalities were uncommon (M: 37% vs F: 77%, p < 0.001), while impaired rectal sensation (M: 24% vs F: 7%, p = 0.001) and functional disturbances of evacuation (M: 36% vs F: 13%, p = 0.001) were more common than in women. No abnormality on all tests performed was observed in twice as many males (M: 18% vs F: 9%, p = 0.10). CONCLUSIONS & INFERENCES: Pathophysiological mechanisms of FI differ between sexes. Anal sphincter dysfunction was an uncommon finding in males, with impaired rectal sensation and functional disturbances of evacuation much more prominent than in the female cohort. These findings are likely to impact options for symptom management.

Irritable bowel syndrome in quiescent inflammatory bowel disease: a review.

Ongoing troublesome bowel symptoms despite quiescent inflammatory disease are a frequent management challenge when caring for patients with inflammatory bowel disease (IBD). Even when active disease has been excluded the prevalence of residual gastrointestinal symptoms is surprisingly high and the cause often obscure. The presence of a concurrent functional disorder such as irritable bowel syndrome (IBS) is associated with worse quality of life, worse physical functioning, higher prevalence of anxiety and greater health care utilization. Potential etiological mechanisms leading to the development of IBS like symptoms include the development of visceral hypersensitivity following the original inflammatory insult, alteration in cortical processing, dysbiosis and residual subacute inflammation. Therapeutic options for managing IBS in patients with IBD include dietary modification, interventions targeted at correction of visceral sensory dysfunction or cortical processing and modulation of the gut microbiota. As there are few studies specifically examining the treatment of IBS in patients with IBD, the majority of therapeutic interventions are extrapolated from the IBS literature. Given the frequency of residual functional symptoms in IBS, significantly more research is warranted in this field.

Assessment of rectal afferent neuronal function and brain activity in patients with constipation and rectal hyposensitivity.

BACKGROUND: Blunted rectal sensation (rectal hyposensitivity: RH) is present in almost one-quarter of patients with chronic constipation. The mechanisms of its development are not fully understood, but in a proportion, afferent dysfunction is likely. To determine if, in patients with RH, alteration of rectal sensory pathways exists, rectal evoked potentials (EPs) and inverse modeling of cortical dipoles were examined. METHODS: Rectal EPs (64 channels) were recorded in 13 patients with constipation and RH (elevated thresholds to balloon distension) and 11 healthy controls, in response to electrical stimulation of the rectum at 10 cm from the anal verge using a bipolar stimulating electrode. Stimuli were delivered at pain threshold. Evoked potential peak latencies and amplitudes were analyzed, and inverse modeling was performed on traces obtained to determine the location of cortical generators. KEY RESULTS: Pain threshold was higher in patients than controls [median 59 (range 23-80) mA vs 24 (10-55) mA; P = 0.007]. Median latency to the first negative peak was 142 (±24) ms in subjects compared with 116 (±15) ms in controls (P = 0.004). There was no difference in topographic analysis of EPs or location of cortical activity demonstrated by inverse modeling between groups. CONCLUSIONS & INFERENCES: This study is the first showing objective evidence of alteration in the rectal afferent pathway of individuals with RH and constipation. Prolonged latencies suggest a primary defect in sensory neuronal function, while cerebral processing of visceral sensory information appears normal.