HOW USEFUL ARE MANOMETRIC TESTS OF ANORECTAL FUNCTION IN THE MANAGEMENT OF DEFECATION DISORDERS

Objectives: The clinical usefulness of assessing anorectal physiology has not been systematically examined. Our aims were to evaluate whethe r manometric tests of anorectal function influence the management and outcome of patients with defecation disorders, and to identify the pat ients who may most benefit from this assessment. Methods: Using a stan dard protocol of anorectal manometry rectal sensation, saline continen ce, simulated defecation, and pudendal nerve terminal latency tests, w e studied 143 consecutive patients (m/f = 27/116) and followed their p rogress over 18 months. Results: Tests of anorectal function in 126 (8 8%) patients revealed new information that led to a change in the mana gement of 108 (76%) patients. Among 69 patients referred with constipa tion, 33 (48%) had obstructive defecation, and 40 (58%) had impaired r ectal sensation; 30 (43%) improved after biofeedback therapy. Among 56 patients referred with fecal incontinence, 55 (98%) had manometric ab normalities: 30 (53%) had a low squeeze sphincter pressure, 20 (36%) h ad impaired rectal sensation, and 28 (50%) had pudendal neuropathy. Th iry-four (60%) patients were referred for biofeedback therapy and 11 ( 20%) for surgery. Of these, 15 completed biofeedback therapy with impr ovement, and six had successful surgery. Seven of 10 (70%) patients re ferred for preoperative evaluation had abnormalities that contraindica ted surgery. Conclusions: Manometric tests of anorectal function provi de not only an objective diagnosis but, also, a better understanding o f the underlying pathophysiology. In addition, it provides new informa tion that could influence the management and outcome of patients with disorders of defecation.