What are the symptoms of lactose intolerance?

Lactose intolerant children can have painful symptoms after eating or drinking dairy products. Common symptoms include:

• Bloating

• Extra gas

• Upset stomach (nausea)

• Vomiting

• Diarrhea

• Belly pain or cramping

Symptoms happen 30 minutes to 2 hours after having milk or milk products. Symptoms range from mild to severe. This depends on how much lactose your child ate or drank and the amount they can handle. 

How is lactose intolerance diagnosed?

The most common test used to diagnose lactose intolerance is called the hydrogen breath test. This test measures the level of a gas called hydrogen in your child’s breath. Hydrogen is made by bacteria in the large intestine (colon) in response to undigested lactose. Hydrogen is carried through the bloodstream to the lungs, where it's breathed out. High levels of hydrogen in your child’s breath means that lactose isn't being digested correctly. Other tests include stool tests which measure the amount of undigested sugar or acidity in the stool as a marker of undigested lactose. Sometimes your child will need an endoscopy. During this procedure with sedation, small tissue samples may be taken from the small intestine to measure lactase levels directly from the intestine. The absence of lactase shows a lactose intolerance. 

How is lactose intolerance treated?

One way to manage your child’s symptoms is to reduce or eliminate sources of lactose. This includes most dairy products, such as:

• Milk

• Butter

• Cream

• Cheese

• Ice cream

Children with lactose intolerance can sometimes eat or drink dairy products without symptoms. At first your child’s healthcare provider may want to remove all lactose from your child’s diet to stop symptoms. Then you can work with the provider to learn what kinds of dairy products your child can handle. Ask your provider about using milk substitutes, such as soy, rice, and oat milk. Your child's provider may advise a lactase enzyme supplement to help your child digest lactose without having symptoms.

Kids need calcium and vitamin D

Dairy products are a good source of calcium and vitamin D. Kids need calcium and vitamin D for bone growth and strength. Talk with your child’s healthcare provider about ways to give your child enough calcium and vitamin D. Foods that contain calcium include:

• Green vegetables, such as broccoli, kale, bok choy (Chinese cabbage), and turnip greens

• Cooked spinach

• Fish with edible bones, such as canned salmon or sardines

• Alfalfa or soy sprouts

• Tofu, soybeans, pinto beans, and navy beans

• Almonds

• Sesame seeds

• Molasses

• Calcium-fortified drinks, such as orange juice, soymilk, and rice milk

• Lactose-free milk and other lactose-free dairy products

• Orange and grapefruit juice