Effect of misoprostol on postprandial intestinal motility and orocecal transit time in humans

We measured the effect of misoprostol (M), a PGE1 analog, on duodenojejunal postprandial motor activity and orocecal transit in eight healthy volunteers. Intestinal motility was studied by an intraluminal catheter with three strain gauge transducers connected to a solid-state datalogger, and transit time was measured by a hydrogen breath test. Subjects were studied for two consecutive days and fed twice a day with a similar, 600-kcal meal. Misoprostol (M) at 800, 400, or 200 micrograms or placebo were taken orally before every one of the four meals. Transit time was measured after the morning meal on both days, after ingestion of either 800 micrograms of M or placebo. On four occasions, following M, the normal fed pattern was not established and the migrating motor complex (MMC) was not interrupted by the meal. In all other occasions, when the higher doses of M were given, the first 1-2 hr after the meal revealed a hypoactive bowel. This effect was inconsistently seen following 200 micrograms of M. Orocecal transit time was consistently and significantly shorter after M than placebo: 48.3 +/- 9.5 min vs 104.4 +/- 4.8 min, P < 0.0001. Four subjects had diarrhea during the study. We conclude that misoprostol, particularly at higher doses, has a profound effect on intestinal postprandial motility and results in accelerated transit time. The motility changes induced by M may be responsible, in part, for its effect on transit.