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).

Living With Lactose Intolerance

Severity of lactose intolerance can vary widely between kids. Because each case is different, there's no one simple way of dealing with it. Each child needs to learn the strategies that work best depending upon the symptoms and how much, if any, lactase the body produces. It may help to keep a food diary as you figure out what foods and drinks your child's system can and can't tolerate.

Many foods, drinks, and digestive aids are available for those with a lactose intolerance (like milk specifically made for people with this condition, which most supermarkets carry). Ask your doctor if your child should supplement certain dairy products with drops or tablets that contain the lactase enzyme.

While kids with the most severe cases may have to avoid all dairy products, doctors now recommend that most have some dairy products in order to get adequate calcium, vitamin D, and protein. Many kids can have small amounts of dairy products — which should be consumed in combination with other foods that don't contain lactose — and some can have one to two glasses of milk each day without any problems, especially if consumed with other non-dairy foods.

Also, kids with lactose intolerance may find that other dairy products, such as yogurt and cheeses, are easier to digest than milk. Lactose-free milk is also a great way to get calcium in your child's diet without the problems. A lactase enzyme supplement can be used, too. Taking this before eating foods that contain dairy will help the body digest the lactose sugar in dairy and prevent the symptoms of lactose intolerance, like pain, cramping, bloating, gas, and diarrhea.

Encourage your child to eat other calcium-rich foods that don't have lactose, such as broccoli, collard greens, kale, turnip greens, salmon, almonds, soybeans, dried fruit, fortified orange juice, and tofu.

Also, consider talking with a registered dietitian to come up with dairy alternatives and a well-balanced diet that provides vital nutrients for your child.

Reviewed by: J. Fernando del Rosario, MD
Date reviewed: October 2011