Lactose intolerance
Millions of people around the world have lactose intolerance. In fact, in some areas of the world, the lactose intolerant outnumber those who can digest lactose, a sugar found in milk and milk products. This type of food intolerance causes mild to severe abdominal pain depending where you place on the tolerance scale, says Patricia L. Raymond, an assistant professor of clinical internal medicine at Eastern Virginia Medical School.