After drinking milk or eating ice cream, does your child have stomach cramps or get diarrhea? If so, your child may have lactose intolerance.

Lactose intolerance can make your child quite uncomfortable, but small changes in your child's diet may help treat the problem.

Read more to learn about what lactose intolerance is and how to help your child live with it.

What is lactose intolerance?

Lactose intolerance occurs in people who can't digest lactose. Lactose is the sugar found in milk. It also is found in other dairy products, such as ice cream and soft cheeses. People who are lactose intolerant don't make enough lactase. Lactase is a natural enzyme made by your intestinal tract that digests lactose. When there isn't enough lactase, lactose that is eaten isn't digested and stays in the intestines causing gas, bloating, stomach cramps, and diarrhea.

Many parents confuse the terms lactose intolerance and milk allergy. While they may share similar symptoms, they are entirely different conditions. Lactose intolerance is a digestive problem, while milk allergy involves the immune system. Your child can be tested for milk allergy or lactose intolerance.

Temporary lactose intolerance

It's rare for a baby to be born with lactose intolerance. However, after a bout of severe diarrhea, which can temporarily affect the ability to produce lactase, a toddler or older child may have trouble digesting milk for 1 to 2 weeks. Drinking milk or eating certain dairy foods may result in the common symptoms of lactose intolerance and more diarrhea.

If your toddler or older child wants milk and has these symptoms, use only lactose-reduced or lactose-free milk for 1 to 2 weeks. Yogurt and aged cheeses usually are digestible because the lactose is broken down when they're made.

Who gets lactose intolerance?

Between 30 and 50 million people in the United States are lactose intolerant. If your child is lactose intolerant, you may see symptoms around the time he starts school or during the teen years.

One cause of lactose intolerance is genetic. Certain ethnic groups are more likely to become lactose intolerant. About 90% of Asian Americans, 80% of African Americans, 62% to 100% of American Indians, 53% of Mexican Americans, and 15% of people of northern European descent are lactose intolerant.

Lactose intolerance also can occur in people who have a disease affecting the small intestine, such as celiac disease or Crohn disease.

What are the symptoms?

Common symptoms of lactose intolerance include

• Stomach cramps

• Bloating

• Gas

• Diarrhea

• Nausea

These symptoms usually begin about 30 minutes to 2 hours after drinking or eating foods containing lactose.

How do I know if my child is lactose intolerant?

One way to check if your child has trouble digesting lactose is to take all milk products out of your child's diet for 2 weeks and see if symptoms improve. After 2 weeks, slowly reintroduce them in small amounts each day to see if symptoms return.

Because many non-dairy and prepared foods contain lactose, it may be hard to remove all of these food from your child's diet. (See "Other foods that may contain lactose.")

If you think your child is lactose intolerant, talk with your pediatrician. Your child may need to be tested. The most common test for lactose intolerance is the lactose breath test. It's also called the hydrogen breath test. This test measures hydrogen levels in the breath after a lactose solution is swallowed. Normally, hydrogen is found only in low levels in a person's breath. However, when lactose isn't digested, it ferments in the intestines and produces hydrogen, which then will be exhaled through the lungs.

Your pediatrician may refer you to a specialist. If needed, a specialist can measure lactase and other enzymes from a small intestine sample. The sample usually is obtained during a diagnostic endoscopy. This procedure lets doctors view the inside of the intestines and obtain tissue samples.

Other foods that may contain lactose

You and your child must become expert label-readers to know what foods contain lactose. The following words on a food label may mean that the food contains lactose:

• Whey

• Curds

• Milk by-products

• Dry milk solids

• Non-fat dry milk powder

Lactose also may be added to many non-dairy and prepared foods. If your child has a very low tolerance for lactose, she may be sensitive to the following food products that may contain lactose:

• Bread, baked goods

• Breakfast cereals and drinks

• Instant potatoes and soups

• Margarine

• Lunch meat (not including kosher meat)

• Salad dressing

• Candy

• Snack foods

• Dry mixes for pancakes, biscuits, and cookies

• Powdered coffee creamer

• Non-dairy whipped topping

What changes can help my child?

There is no cure for lactose intolerance. However, if your child is lactose intolerant, diet changes can make a big difference. You can help decide what changes are best for your child.

• By trial and error. In time your child will learn, by trial and error, how much milk or milk-based foods she can handle. Younger children with lactose intolerance should avoid foods containing lactose. These foods include milk, ice cream, and soft cheeses, such as cottage cheese, American cheese, and mozzarella. Older children usually can eat small amounts of lactose-containing foods, particularly if the foods are eaten as part of a meal and not alone. Many children can keep eating yogurt and aged cheeses, such as Swiss, cheddar, and Parmesan.

• Over-the-counter lactase. Give your child over-the-counter lactase right before each meal. This may help her body digest foods that contain lactose.

• Lactose-free or lactose-reduced. Offer your child lactose-free or lactose-reduced milk and other dairy products. Lactose-reduced milk retains all the ingredients of regular milk. You can store it in the refrigerator the same length of time.

Other sources of calcium

In the rare cases in which all milk and dairy products have to be avoided, it's important that your child get other sources of calcium. A variety of calcium-rich foods include

• Broccoli

• Pinto beans

• Sweet potatoes

• Turnips

• Collard greens

• Lettuce greens such as spinach and kale

• Canned fish with bones such as sardines, salmon, and tuna

• Tofu

• Oranges

• Juices with added calcium

If your child isn't getting the daily recommended amount of calcium (see chart), your pediatrician may recommend a calcium supplement.

Remember

Lactose intolerance doesn't have to make your child's life miserable. There are many options for children who are lactose intolerant. Talk with your pediatrician about what products or diet changes would be best for your child.