A diarrhea that results from increased motility in the bowel; significant increases in bowel motility can deliver excessively large volumes of stool to the colon. Diarrhea can result when the maximum colonic absorptive capacity of 4 liters a day is exceeded. Also, an alteration in colonic motility such that bowel contents are emptied before adequate absorption can occur has been offered as a possible explanation for the diarrhea associated with irritable bowel disease.