What is Lactose Intolerance?

Lactose is a disaccharide that cannot be absorbed by the body as it is, but has to be broken down into glucose and lactose by the lactase enzyme. Lactase is found in the external membrane of the bush border of epithelium cells in the intestinal mucous. An infant may be born with a lack of lactase, or this may be caused by lesions in the intestinal mucosa brought about by a gastrointestinal infection. An infant might have a complete lack of the enzyme, or a partial lack. With lactase deficiency, lactose is not broken up and cannot be absorbed. This leads to diarrhea and an increased loss of fluids and electrolytes and also to lactose accumulating in the intestine. There, it is fermented by the intestinal bacteria which causes more gases to be produced. This, in turn, leads to flatulence and abdominal pain.