In lactose intolerance, the body cannot digest lactose, a natural sugar in milk and dairy products. The condition usually appears in adolescence or adulthood and is more common in those of African, Native American, Asian, or Jewish origin.
The cause is lack of the enzyme lactase, which breaks down lactose. High levels of the enzyme are present at birth, but in many ethnic groups levels naturally drop with age, eventually resulting in lactose intolerance.
Symptoms usually appear within a few hours of consuming products containing milk.
They typically include gas (flatus), abdominal bloating and cramping, diarrhea, and vomiting.
The condition is usually lifelong, but symptoms can be avoided by following a lactose-free diet. In addition, a doctor may suggest supplements to improve digestion of lactose