lactose intolerance is a common problem. it happens when your body does not have enough lactase which is an enzyme produced in the small intestine. lactase is necessary to digest lactose – the natural sugar found in milk and other dairy products. in the intestines undigested lactose leads to the buildup of gas. within 30 minutes to 2 hours after eating dairy products containing lactose people with lactose intolerance start to develop stomach cramps and diarrhea. these two symptoms must be present for a person to be diagnosed with lactose intolerance. between 30 and 50 million americans are lactose intolerant. the disorder is more common in some ethnic groups than in others. for example up to 75 percent of all adult african americans and native americans and 90 percent of asian americans are considered to be lactose intolerant. in contrast people of northern european descent are less likely to be lactose intolerant.
what is lactose intolerance?