Diarrhea is a condition in which bowel movements are loose and watery, and occur more frequently than usual, often with urgency. It occurs when the food and liquids move too quickly through the colon (the large intestine) without fluids being absorbed normally. Though diarrhea ordinarily lasts only a day or two and resolves without medical treatment, it can sometimes be chronic, lasting for weeks or more. A doctor should treat this condition if it persists for more than two days or if it is accompanied by dehydration, a high fever, bloody or black stool or severe abdominal pain. Young children may need to be treated by a doctor if diarrhea persists for 24 hours when symptoms of dehydration are also present. Signs of dehydration in babies can include dry mouth, a sunken appearance of the face or abdomen, skin that does not bounce back when pinched and released or if the baby has not had a wet diaper in three hours.