Effects of high dose antacids on bowel motility

The effect of two antacid preparations containing magnesium and aluminum (Riopan, Maaloxan) on stool frequency, stool consistency, stool weight and oro-anal transit time was tested in a randomized, controlled, double-blind study in 10 healthy volunteers. Both antacids increased stool weight and stool frequency, and lowered stool consistency. The oro-anal transit time was not affected. Antacid-induced diarrhea apparently depends more on changes of transmural fluid transport than on changes of intestinal motility. Thus, secretory and osmotic diarrhea can occur without accompanying changes in gastrointestinal motility.