Lactose intolerance

Lactose intolerance, or the inability to digest milk sugar, is a disorder caused by the lack of the enzyme lactase.

The milk contains a lot of lactose, which is a sugar, but different from the table sugar. Milk sugar is composed of glucose and galactose. Before passing through the intestinal wall into the blood stream, it needs to be broken in two constituent parts. The process of digestion takes place in the small intestine, with the aid of digestive juices which contain the enzyme lactase. The latter breaks the bond between the two parts, which are then individually absorbed into the blood stream.

Sometimes, there is not enough lactase in the intestine, which causes the lactose to remain undigested. Thus, lactose moves forward into the large intestine, where the bacteria in the intestinal microflora begins to feed on it. The bacteria can break down lactose, but when doing so, they produce a lot of gas as well as other metabolites which stimulate a faster bowel movement. This results in bloating, which can also become painful, gurgling, rumbling in the intestines, and diarrhoea.

What is lactose intolerance?

Lactose intolerance is not an allergy.

Allergy to milk is a different disorder, caused by intolerance to the protein in milk, and exhibits other, sometimes serious consequences. In the case of milk allergy, a repeated complete exclusion of dairy products from the diet is required.

In some exceptional cases, the patient may suffer from both diseases at the same time, so the diagnosis must be always confirmed by a doctor.

Galactosemia is a rare metabolic disorder which is revealed in early childhood. These patients must not drink any milk, not even lactose-free milk.

What kind of problems are caused by lactose intolerance and when?

How to diagnose lactose intolerance