Lactose intolerance is the malabsorption of milk sugar (lactose) caused by the deficiency of the enzyme lactase, which breaks down lactose in the small intestine. Lactose intolerance can cause bowel problems as the deficiency of the enzyme causes lactose to remain in the bowel and travel with other contents of the bowel instead of being absorbed into the bloodstream.
Although lactose intolerance is caused by digesting food, it is not an allergy and it should not be confused with milk allergy, for example. Lactose intolerance is most common among adults and older schoolchildren. Lactose intolerance can also be a symptom of coeliac disease.
Symptoms of lactose intolerance
In most cases, the symptoms of lactose intolerance are experienced 1–3 hours after digesting food that contains lactose. The most common symptoms include:
- Stomach bloating
- Watery stool
- Indeterminate abdominal pain
The severity of symptoms varies between individuals and depends on the amount of dairy products digested. Many people with lactose intolerance can eat reasonable amounts of lactose, but the most sensitive can experience stomach problems even after eating small amounts of food with lactose.
Examination and treatment of lactose intolerance
Lactose intolerance is most likely if you suspect you have the condition and the symptoms subside after avoiding dairy products for a while. In such cases, the diagnosis does not need to be verified with a laboratory test. You can treat the symptoms yourself by eating and drinking less dairy products or avoiding them altogether.
You should visit a doctor for examinations if your stomach symptoms are severe and they are not clearly linked to any dairy products. In such cases, it is easy to diagnose lactose intolerance with a simple laboratory test by performing a gene test on a blood sample. A previously standard lactose tolerance test is not required.
If you continue to experience clear symptoms despite a lactose intolerance diagnosis and avoiding dairy products, you should seek medical attention for additional examinations; for example, to rule out the possibility of coeliac disease.