Lactose Intolerance

About Lactose Intolerance

For many kids, an ice cream sundae or a cool glass of milk at lunch means an afternoon of cramps, gas, and diarrhea.

Kids who have this kind of discomfort after consuming dairy products might have a lactose intolerance, which is caused by problems digesting lactose, the main sugar in milk and milk products.

Lactose intolerance occurs when the body makes too little of the enzyme lactase, which is needed to break down lactose into two smaller sugars called glucose and galactose. When there's not enough lactase in the body, lactose doesn't get broken down in the small intestine, and it passes into the large intestine where bacteria ferment it into gases and acids.

This process can cause cramps, abdominal pain, gas, and diarrhea about 30 minutes to 2 hours after consuming any foods or drinks that contain lactose.

For some kids, these symptoms are very severe and their systems can't tolerate any lactose. For others, the symptoms are milder and they just have to limit the amount of dairy products they consume.

Lactose intolerance can be managed — and the stomach discomfort can be reduced — with some modifications to the diet. If you suspect that your child has a lactose intolerance, contact your doctor.

Who Gets Lactose Intolerance?

Lactose intolerance is more common among people of Asian, African, Native American, and Hispanic descent.

In most people, lactose intolerance remains a lifelong problem. But for some kids, it can be a temporary condition that begins after they take certain antibiotics or have gastrointestinal infections and eventually goes away.

Diagnosing Lactose Intolerance

Doctors typically diagnose lactose intolerance through a simple hydrogen breath test. A person blows into a tube to give a sample of the breath, then gives another sample after drinking a lactose solution or eating a lactose-containing food.

If someone has a lactose intolerance, the test will show that there is a higher than average level of hydrogen and methane in the breath. That's because undigested lactose leads to higher levels of these gases in the system, which can be detected in the breath.

Because certain foods, medications, and exposure to cigarette smoking can affect the test's accuracy, the doctor might recommend taking certain precautions before the test is done.

In addition to the breath test, doctors usually do a physical exam and take a full medical history to rule out other medical conditions.

Problems digesting lactose can also occur in people with other diseases of the gastrointestinal tract, such as celiac disease, a condition in which the intestine becomes damaged due to the person's abnormal sensitivity to gluten (a protein found in wheat and certain other grains).