Altered recto‐anal motility in irritable bowel syndrome: a clinical physiological study of 80 Mexican patients

Abstract

AbstractBetween 1989 and 1991, 347 out‐patients suffering from functional bowel disease were studied. Eighty (mean age 33.4 ± 1, range 17–53 years: 75 females) met the established criteria for irritable bowel syndrome. After noting their clinical history, they underwent standard laboratory tests, air contrast barium enema, recto‐sigmoidoscopy; rectal sensitivity studies, and recordings of both electrical and mechanical activities of the distal rectum and the internal anal sphincter during 2 h inter digestive and 2 h post‐prandial periods. Twenty‐one normal subjects served as a control group. In the irritable bowel syndrome, both basal (P = 0.01) as well as post‐prandial (P = 0.003) rectal spike amplitudes were higher compared with controls. While there was no significant difference in the induced recto‐anal inhibitory reflex, the frequency (P = 0.001), duration (P = 0.007) and amplitude (P = 0.03) of spontaneous anal relaxations were all greater in the patients compared with the control. Patients perceived the rectal sensation and discomfort at significantly lower values than normal subjects (P < 0.01). In summary, irritable bowel syndrome patients showed increased electrical activity of the rectum in response to food and increased frequency, duration, and amplitude of the naturally occurring recto‐anal inhibitory reflex, and a sensitive rectum.