Lactase deficiency in patients with the 'irritable-colon syndrome'

SEVERAL recent studies suggest that lactase deficiency is common in the adult. It may be present as an isolated enzyme defect1 2 3 4 5 or may accompany organic disease of the small bowel.6 7 8 The symptoms attributed to lactase deficiency —abdominal cramps, distention, flatulence and diarrhea — result from a failure to hydrolyze and absorb ingested lactose. Increased intestinal peristalsis, with passage of acid, watery stools, may be due both to an osmotic shift of fluid into the lumen and to the action of lactic and acetic acids resulting from bacterial fermentation of lactose.9 These symptoms disappear when lactose is eliminated from the diet. . . .