(HealthDay News) -- Lactose intolerance means the body has difficulty digesting a sugar called lactose, found in milk and other dairy products. It occurs when the body lacks enough of an enzyme called lactase, says the U.S. National Digestive Diseases Information Clearinghouse.
Some people may be predisposed to lactose intolerance because of family history, while others may develop it from a medical problem, including celiac disease or Crohn's disease.
Adults and premature babies are more likely than others to develop lactose intolerance, the agency says. Certain ethnic groups are also at an increased risk, such as African Americans, Hispanics, Asians and American Indians.