Allen came to the clinic because he was suffering from severe diarrhea. He was seen by Gregory House and told him that he was using the bathroom up to 12 times a day and it was interfering with his job as a flight attendant. Allen put down the diarrhea to his recent decision to quit smoking as that's when it started. Allen was considering starting smoking again. When Dr. House asked how many packs, Allen said only about one a day, but Dr. House said he wasn't asking about cigarettes. Dr. House had noted Allen was chewing gum to deal with the oral cravings people who quit smoking often experience. Allen said he used about six packs of gum a day. Dr. House confirmed it was sugarless gum and told Allen that although the gum uses sorbitol as an artificial sweetener, doctors use it as a laxative. Allen realized immediately what the problem was and took the gum out of his mouth immediately.