Inhibition of gastric secretion relieves diarrhea and postprandial urgency associated with irritable bowel syndrome or functional diarrhea.

Five patients with gastroesophageal reflux disease (GERD), who also had chronic functional diarrhea and postprandial urgency, unexpectedly noted rapid relief of their diarrhea and urgency when they took lansoprazole for their heartburn. To determine if this surprising result was not fortuitous, all 20 patients seen during the next six months for chronic diarrhea and postprandial urgency due to irritable bowel syndrome (IBS) or functional diarrhea were treated with inhibitors of gastric secretion: 14 with proton-pump inhibitors and 6 with H2 blockers. All patients had rapid, marked improvement. Usually within three days, their symptoms abated and they usually had one to three formed stools per day. Relief continued during the one to six months they were followed on therapy. Five patients stopped therapy, had recurrent diarrhea, and rapid relief upon resuming therapy. Thus, inhibition of gastric secretion effectively controls the diarrhea and postprandial urgency associated with IBS or functional diarrhea, probably by diminishing the gastrocolic or gastroenteric reflex.