The sugar found in milk and other dairy products such as yoghurt and cheese is called lactose. An enzyme in the small intestine called “lactase” breaks lactose into galactose and glucose. When the lactose is not digested properly by the small intestine, it passes unbroken into the colon. The bacteria in the colon break the lactose down into hydrogen and carbon dioxide. People who fail to digest lactose in their small intestines are diagnosed with lactose intolerance.
Usually lactose intolerance only affects adults, but sometimes children do suffer from it. For children, their symptoms can be mild or very severe (for example, cramps, diarrhoea in children, etc.)
Normally, parents can confuse milk allergy with lactose intolerance. They do share the same symptoms, but they are completely different medical conditions. Milk allergy is caused by the immune system while lactose intolerance is a problem with the digestive system.
The causes of lactose intolerance include:
1. Absence or deficiency of the lactase enzyme
2. Infections in the gastrointestinal tract that damage the lining inside the small intestine
3. Gluten intolerance (It affects lactase production)