Effect of biofeedback therapy on anorectal physiological parameters among patients with fecal evacuation disorder.

Abstract

Though biofeedback therapy is often effective in patients with fecal evacuation disorder (FED), a common cause of chronic constipation (CC) in tertiary practice, data on anorectal physiological parameters following it are scanty. Consecutive patients with FED with CC diagnosed by abnormalities in at least two of the three tests (anorectal manometry, defecography, and balloon expulsion test [BET]) undergoing biofeedback (two sessions per day, 30min each, for 2weeks) during a 3-year period were analyzed. Clinical evaluation, anorectal manometry (ARM), and BET were performed at the beginning and after biofeedback. Incomplete evacuation 42/43 (98%), straining 40/43 (93%), and feeling of outlet obstruction 35/43 (81%) were the most common symptoms among these 43 patients (median age 44years, range 18-76, 30 [71%] male). All the three tests (defecography, BET, and ARM) were abnormal in 17 (40%) patients and the others had two abnormal tests. Improvement in physiological parameters was noted following biofeedback (median residual anal pressure during defecation 99mmHg (range 52-148) vs. 78mmHg (37-182), p=0.03; maximum intra-rectal pressure 60mmHg (90-110) vs. 76mmHg (31-178); p=0.01; defecation index 1.1 (0.1-23.0) vs. 3.2 (0.5-29.0); p=0.001). Dyssynergia on ARM and BET got corrected in 22/34 (65%) and 18/30 (60%) patients. At a 1-month follow up, 23/37 (62%) patients reported satisfactory symptomatic improvement. Biofeedback not only improves symptoms but also anorectal physiological parameters in patients with FED.