(HealthDay News) -- Lactose intolerance occurs when the body can't digest lactose, a sugar found in dairy products.
The U.S National Library of Medicine mentions these common reasons for lactose intolerance:
- The small intestine doesn't produce enough of the enzyme lactase.
- Premature birth.
- Bowel surgery.
- A bacterial or viral infection in the small intestine.
- An intestinal disease, such as celiac sprue.