Colon motility and colo-anal reflexes in chronic idiopathic constipation. Effects of a novel enterokinetic agent cisapride.

Motor activity of the colon and reflex behaviour of the anal sphincters in normal subjects and in patients with idiopathic constipation were studied using a novel probe with 5 open-end tips to measure pressures, and 3 balloons for stimulation of the distal colon. Constipation appeared to be associated with an increased threshold of the inhibitory relaxation reflex of the internal anal sphincter (41.7 in normals and 65.7 in patients), and in particular with a blunted sensation of the defaecation urge (51.0 in normals and 112.8 in patients). Single-blind comparison with a placebo showed that cisapride, a new gastrointestinal prokinetic substance, had a significant effect on the sensation threshold, which normalized or improved in 15 out of the 16 patients studied.