What is lactose intolerance in children?

Lactose intolerance is when the body can’t easily break down or digest lactose. Lactose is a sugar found in milk and milk products.

If your child is lactose intolerant, your child may have unpleasant symptoms after eating or drinking milk products. These symptoms include bloating, diarrhea, and gas.

Lactose intolerance is different from having a food allergy to milk.

What causes lactose intolerance in a child?

Lactose intolerance happens when the small intestine doesn’t make enough of a digestive juice, or enzyme, called lactase. Without enough lactase, the body can’t break down or digest lactose.

Lactose intolerance can happen to both children and adults. Some common causes include:

• Digestive diseases or infection

• Injury to the small intestine

• Family history of lactose intolerance. In these cases, over time the body may make less of the lactase enzyme. Symptoms may occur during the teen or adult years.

• A baby being born too early, also called a premature baby. This type of lactose intolerance is often a short-term problem that goes away.

In very rare cases, some newborns can’t make any lactase from birth.

Which children are at risk for lactose intolerance?

Lactose intolerance can happen to anyone. But your child is more at risk for lactose intolerance if your child:

• Is a baby who was born too early (premature). This type of lactose intolerance is often a short-term problem that goes away.

• Is African American, Jewish, Mexican American, American Indian, or Asian American

• Has a family history of lactose intolerance. Symptoms may occur during the teen or adult years.

What are the symptoms of lactose intolerance in a child?

Symptoms often begin to appear in white children after age 5. They appear in African-American children as young as 2 years old.

Symptoms begin about 30 minutes to 2 hours after having foods or drinks containing lactose. Each child’s symptoms may vary. Symptoms may include:

• Upset stomach or nausea

• Cramps

• Bloating

• Belly (abdominal) pain

• Gas

• Loose stool or diarrhea

• Vomiting, happens more often to teens

How severe your child’s symptoms are will depend on how much lactose your child has had. It will also depend on how much lactase your child’s body makes.

The symptoms of lactose intolerance may look like other health conditions. Always see your child's healthcare provider for a diagnosis.

How is lactose intolerance diagnosed in a child?

Your child’s healthcare provider will give your child a physical exam and take a health history.

Your child may need to be tested. The most common tests used to check how lactose is absorbed in the digestive system include:

• Lactose tolerance test. This test checks how lactose is absorbed by your child’s digestive system. After fasting, your child drinks a liquid that has lactose. The urine is checked for glucose levels. The hydrogen breath test is done more commonly.

• Hydrogen breath test. Your child drinks a liquid that has a lot of lactose. The breath is then checked at regular times to measure the amount of hydrogen. High levels of hydrogen mean your child is lactose intolerant.

• Stool acidity test. This test is used for babies and young children. It checks how much acid is in the stool. If your child is not digesting lactose, the stool will have lactic acid, glucose, and other fatty acids.

• Occasionally, a small bowel biopsy (sample) is sent for testing

How is lactose intolerance treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

No treatment will help your child’s body make more lactase. But you can manage your child’s symptoms with a diet that limits lactose. Your child may not have to stop eating all foods with lactose. Your child's healthcare provider may also suggest your child take lactase enzymes. They are sold over the counter.

Here are some tips for managing lactose in your child’s diet:

• Start slowly. After a week of limiting foods with lactose, try adding small amounts of milk or milk products back to your child’s diet. Watch to see if your child has any symptoms. Note which foods your child can handle and which foods your child should not eat.

• Have milk and milk products with other foods. You may find your child has fewer symptoms if your child has milk or milk products with meals. Have your child try eating cheese with crackers. Or let your child have milk with cereal.

• Choose dairy products with naturally lower levels of lactose. These include hard cheeses and yogurt.

• Look for lactose-free and lactose-reduced milk and milk products. These can be found at many food stores. They are the same as regular milk and milk products. But they have the lactase enzyme added to them.

• Ask about lactase products. Ask your child’s healthcare provider if your child should take a lactase pill or lactase drops when having milk products.

Talk with your child’s provider about what products or diet changes may help your child. You may also find it helpful to see a registered dietitian.

What are possible complications of lactose intolerance in a child?

Lactose intolerance won’t hurt your child’s body. The symptoms are unpleasant, but they are not serious.

How can I help my child live with lactose intolerance?

Lactose intolerance can cause unpleasant symptoms. But in most cases, you don’t need to remove all foods with lactose from your child's diet. By watching your child's symptoms, you can find out which foods they can handle. You can also tell which foods your child should stay away from.

When foods are removed from your child's diet, you must replace them with other foods that offer needed nutrients. Also make sure that your child has enough calcium and vitamin D. Read nutrition labels on foods. The bottom section of the label contains information on calcium and vitamin D.

Talk with your child’s healthcare provider about what products or diet changes may help your child. You may also find it helpful to see a registered dietitian.

When should I call my child's healthcare provider?

The symptoms of lactose intolerance may look like symptoms of other disorders. Have your child checked by a healthcare provider if your child has:

• Loose stool or diarrhea

• Swelling or bloating

• Belly pain

• Other GI (gastrointestinal) symptoms

Key points about lactose intolerance in children

• Lactose intolerance is when your child’s body can’t easily break down, or digest, lactose. Lactose is a sugar found in milk and milk products.

• It happens when the small intestine doesn’t make enough of a digestive juice, or enzyme, called lactase.

• Your child may have uncomfortable symptoms, such as bloating, gas, and an upset stomach after eating or drinking milk or milk products.

• Have your child see a healthcare provider for a diagnosis.

• You can manage your child’s symptoms by limiting foods that have lactose.

• Children and teens need calcium and vitamin D for bone growth and health. Read food labels so you can check that your child gets the right amount of these nutrients.

• Ask your healthcare provider for help if you have concerns about developing a lactose-intolerant dietary plan

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s healthcare provider after office hours. This is important if your child becomes ill and you have questions or need advice.