Although such discharge increases fluid and electrolyte loss , it also moves the infected feces out of the intestine more rapidly and speeds recovery from the disease. Diarrhea can also occur when there is inadequate time to reabsorb the normal amount of water from the feces. Increased motility decreases the time feces spend in the colon . For example ,emotional stress can increase parasympathetic stimulation of the digestive tract and cause diarrhea.