congenital lactose intolerance

Last reviewed 01/2018

Congenital lactose intolerance is characterised by severe diarrhoea, abdominal pain and distension that appear soon after birth when the diet begins to contain lactose. The symptoms disappear if milk is withdrawn from the diet. Steatorrhea is not always found. Blood glucose concentrations increase normally after oral administration of glucose or galactose but not after lactose, which may induce explosive diarrhoea, flatulence and intestinal discomfort. The pH of the stool is acidic because of the presence of lactic acid as a result of the bacterial fermentation of the ingested lactose.

There is a marked lactase deficiency in the small intestine.

Treatment is a with a lactose free diet.