ALTERED RECTOANAL MOTILITY IN IRRITABLE-BOWEL-SYNDROME - A CLINICAL PHYSIOLOGICAL STUDY OF 80 MEXICAN PATIENTS

Between 1989 and 1992, 347 out-patients suffering from functional bowe l disease were studied. Eighty (mean age 33.4 +/- 1, range 17-53 years ; 75 females) met the established criteria for irritable bowel syndrom e. After noting their clinical history, they underwent standard labora tory tests, air contrast barium enema, recto-sigmoidoscopy; rectal sen sitivity studies, and recordings of both electrical and mechanical act ivities of the distal rectum and the internal anal sphincter during 2 h interdigestive and 2 h postprandial periods. Twenty-one normal subje cts served as a control group. In the irritable bowel syndrome, both b asal (P = 0.01) as well as post-prandial (P = 0.003) rectal spike ampl itudes were higher compared with controls. While there was no signific ant difference in the induced recto-anal inhibitory reflex, the freque ncy (P = 0. 001), duration (P = 0.007) and amplitude (P = 0.03) of spo ntaneous anal relaxations were all greater in the patients compared wi th the control. Patients perceived the rectal sensation and discomfort at significantly lower values than normal subjects (P < 0.01). in sum mary, irritable bowel syndrome patients showed increased electrical ac tivity of the rectum in response to food and increased frequency, -dur ation, and amplitude of the naturally occurring recto-anal inhibitory reflex, and a sensitive rectum.