Randomized controlled trial of biofeedback, sham feedback, and standard therapy for dyssynergic defecation

Background & Aims: Constipation is a common disorder, and current treatments are generally unsatisfactory. Biofeedback might help patients with constipation and dyssynergic defecation, but its efficacy is unproven, and whether improvements are due to operant conditioning or personal attention is unknown. Methods: In a prospective randomized trial, we investigated the efficacy of biofeedback (manometric-assisted anal relaxation, muscle coordination, and simulated defecation training; biofeedback) with either sham feedback therapy (sham) or standard therapy (diet, exercise, laxatives; standard) in 77 subjects (69 women) with chronic constipation and dyssynergic defecation. At baseline and after treatment (3 months), physiologic changes were assessed by anorectal manometry, balloon expulsion, and colonic transit study and symptomatic changes and stool characteristics by visual analog scale and prospective stool diary. Primary outcome measures (intention-to-treat analysis) included presence of dyssynergia, balloon expulsion time, number of complete spontaneous bowel movements, and global bowel satisfaction. Results: Subjects in the biofeedback group were more likely to correct dyssynergia. (P < .0001), improve defecation index (P < .0001), and decrease balloon expulsion time (P = .02) than other groups. Colonic transit improved after biofeedback or standard (P = .01) but not after sham. In the biofeedback group, the number of complete spontaneous bowel movements increased (P < .02) and was higher (P < .05) than in other groups, and use of digital maneuvers decreased (P = .03). Global bowel satisfaction was higher (P = .04) in the biofeedback than sham group. Conclusions: Biofeedback improves constipation and physiologic characteristics of bowel function in patients with dyssynergia. This effect is mediated by modifying physiologic behavior and colorectal function. Biofeedback is the preferred treatment for constipated patients with dyssynergia.