I have a disagreement to resolve about diarrhea as a result of a food irritation or allergy (as opposed to flu or other) a short time (less than a couple of hours) after ingestion. 1] The food is basically liquified and passes out as diarrhrea. The food eaten is expelled as liquid within those few hours. 2] The food irritates the intestinal lining, causing it to flush with water. The water that exits is simply water that has not been reabsorbed yet (the main purpose of the large intenstine). The food that was eaten does not exit the body in so short a time. Which is closer to correct? Follow-up question: how fast can eaten food plausibly reach the rectum?