Chewing too much sugarless gum can cause diarrhea, according to The Lancet, which has published a case report on a British woman who chewed on up to 60 sticks of gum a day. Doctors were baffled when the 32-year-old air stewardess was admitted to a hospital with chronic severe diarrhea and intestinal pain. Her blood, urine, liver, and intestinal tests were all normal. Finally, she happened to offer an important clue: Her heavy "diet" of sugarless gum introduced 75 grams of sorbitol into her body. This sugar substitute is neither digested nor absorbed by the digestive system and has a laxative effect. When she reduced her intake, she recovered.