Altered temporal characteristics of the rectoanal inhibitory reflex in patients with abdominal distension.

The rectoanal inhibitory reflex (RAIR) is important in gas and stool evacuation. We examined RAIR features in patients with chronic constipation who exhibited bloating with and without abdominal distension, to determine whether alterations in RAIR may be a factor in the pathogenesis of abdominal distension. Seventy-five female patients with chronic constipation with or without abdominal distension were included in the study. The presence or absence of abdominal distension was assessed according to the Rome II questionnaire. All patients underwent both RAIR and rectal sensitivity testing, and specific RAIR parameters were analyzed. Patients were divided into two groups: abdominal bloating with distension (D, n = 55) and abdominal bloating without distension (ND, n = 20). D had a longer time to the onset of anal sphincter inhibition (latency of inhibition) (P = 0.03) compared with ND. In logistic regression analysis, a combination of age, latency of inhibition and the time measured from onset of inhibition to the point of maximum inhibition predicted abdominal distension (P = 0.002). There were no differences between groups for the time from point of maximum inhibition to recovery and for the percentage of internal anal sphincter relaxation. This is the first study to examine the role of RAIR in patients with abdominal distension. Female patients with constipation and abdominal distension exhibited differences in the temporal characteristics of, but not in the degree of, anal sphincter relaxation compared with patients without distension. Since this study was uncontrolled, further studies are necessary to determine the contribution of altered anorectal reflexes to abdominal distension.

Predictors of outcome of anorectal biofeedback therapy in patients with constipation.

BACKGROUND: Anorectal biofeedback therapy (BFT) is a safe and effective treatment in patients with constipation. Given the high prevalence of constipation and therefore high demand for BFT, there is a need to prioritise patients. AIMS: To explore clinical features and anorectal physiology which predict success or failure of BFT and to derive a statistical model which helps to predict the success of BFT. METHODS: A total of 102 patients with constipation referred for BFT were evaluated. All patients underwent comprehensive clinical and anorectal function assessment, including balloon expulsion testing. The BFT protocol consisted of a comprehensive 6-weekly visit programme comprising instruction on toilet behaviour and abdominal breathing, achieving adequate rectal pressure and anal relaxation, and balloon expulsion and rectal sensory retraining. Success of BFT was based on an improvement in global bowel satisfaction. RESULTS: Harder stool consistency (P=0.009), greater willingness to participate (P<0.001), higher resting anal sphincter pressure (P=0.04) and prolonged balloon expulsion time (P=0.02) correlated with an improvement in bowel satisfaction score. A longer duration of laxative use (P=0.049) correlated with no improvement in bowel satisfaction score. Harder stools, shorter duration of laxative use, higher straining rectal pressure and prolonged balloon expulsion independently predicted successful BFT. A model (S(i) = (p)∑ ß(j)X(ij), where ß represents a regression coefficient, X is a given predictive variable and S(i) is the weighted index score for each individual) incorporating these four variables enabled prediction of successful BFT, with sensitivity and specificity of 0.79 and 0.81, respectively. CONCLUSIONS: Important clinical and anorectal physiological features were found to be associated with outcome of anorectal biofeedback therapy in patients with constipation. This information and the predictive model will assist clinicians to prioritise patients for anorectal biofeedback therapy.

Evidence for pelvic floor dyssynergia in patients with irritable bowel syndrome.

PURPOSE: Although functional constipation is known to often manifest concomitant features of pelvic floor dyssynergia, the nature of pelvic floor symptoms and anorectal dysfunction in non-diarrhea predominant irritable bowel syndrome is less clear. This study aims to compare anorectal sensorimotor function and symptoms of patients who have non-diarrhea predominant irritable bowel syndrome with those who have functional constipation. METHODS: We studied 50 consecutive female patients referred with constipation and 2 or more symptoms of pelvic floor dyssynergia, who also satisfied Rome II criteria for either non-diarrhea predominant irritable bowel syndrome (n = 25; mean age, 47 +/- 3 y) or functional constipation (n = 25; 49 +/- 3 y). Assessments included the Rome II Integrative Questionnaire, a validated constipation questionnaire, Hospital Anxiety and Depression scale, visual analog scores for satisfaction with bowel habit and for impact on quality of life, and a comprehensive anorectal physiology study. RESULTS: Both groups displayed physiological evidence of pelvic floor dyssynergia; but patients with non-diarrhea predominant irritable bowel syndrome exhibited a higher prevalence of abnormal balloon expulsion (P < .01) and less paradoxical anal contraction with strain (P = .045) than patients with functional constipation. These patients with irritable bowel syndrome also reported more straining to defecate (P = .04), a higher total constipation score (P = .02), lower stool frequency (P = .02), a trend toward harder stools (P = .06), and less satisfaction with bowel habit (P = .03) than patients with functional constipation. CONCLUSION: Patients with non-diarrhea predominant irritable bowel syndrome with symptoms of pelvic floor dyssynergia exhibit overall pelvic floor dyssynergia physiology similar to that of patients with functional constipation. Certain features, however, such as abnormal balloon expulsion, may be more prominent in the patients with irritable bowel syndrome. Therapeutic modalities, such as biofeedback, that are effective in patients with functional constipation with pelvic floor dyssynergia should therefore be considered in selected patients with irritable bowel syndrome with pelvic floor dyssynergia.