Lactose intolerance

Many people develop lactose intolerance as they age. This digestive disorder can cause a range of uncomfortable symptoms. Our gastroenterologists are here to help.

What is lactose intolerance?

Lactose intolerance is a condition that causes digestive problems after you have milk or milk products. Lactose is a sugar found in milk and milk products, such as butter, cheese and yogurt.

Being lactose intolerant is not the same as having a milk allergy. Lactose intolerance stems from your digestive system being unable to break down lactose. It usually develops during adolescence or adulthood.

A milk allergy is an immune system reaction to one or more proteins found in milk. It most commonly develops in babies less than a year old. Severe allergic reactions can be life-threatening, even when exposed to a small amount of milk or milk product.

Causes of lactose intolerance

Lactose intolerance develops from specific problems in the digestive process. It may occur if you have:

• Lactase deficiency: Your small intestine makes lactase, an enzyme that breaks down lactose. In some people, the small intestine doesn’t make enough of this enzyme to support lactose digestion.
• Lactose malabsorption: This problem can develop from lactase deficiency. Lactose that doesn’t get digested in the small intestine passes into your colon (part of your large intestine). The colon creates fluid and gas as it breaks down undigested lactose.

Lactose intolerance symptoms

Lactose intolerance can cause mild to severe symptoms, depending on how much lactose you consumed and how much your body can digest. You may be able to eat or drink some lactose without having any digestive problems.

Symptoms usually develop between half an hour and two hours after you have milk or milk products. Common symptoms of lactose intolerance include:

• Diarrhea
• Gas
• Nausea
• Stomach bloating or swelling
• Stomach pain

Lactose intolerance diagnosis

Your provider will review your health history, including your family and diet history, to understand your digestive health. They will also ask about your symptoms and do a physical exam of your abdomen.

Your provider may use additional medical tests to diagnose lactose intolerance, including:

• Hydrogen breath test: This test checks the amount of hydrogen in your breath after you drink a beverage that has a certain amount of lactose. Undigested lactose makes hydrogen, so your level will be higher if your body has trouble digesting lactose.
• Stool acidity test: For this test, you provide a stool sample that gets analyzed in a lab. Undigested lactose leads to more lactic acid and other fatty acids in your stool.

Lactose intolerance risk factors

Living with a gastrointestinal condition, such as Crohn’s disease or celiac disease, may make you more likely to develop lactose intolerance. These digestive diseases can harm your small intestine over time and lead to less lactase production.

Your genetics can also influence your small intestine’s ability to create lactase. Having family members with lactose intolerance may increase your risk for the disorder.

Lactose intolerance prevention

You can’t control whether you develop lactose intolerance. But you can prevent uncomfortable lactose intolerance symptoms by managing your diet. Limiting how much lactose you consume or avoiding lactose completely can help.

Your provider can explain which ingredients may cause digestive problems. Lactose is in all milk and milk products. It may also be in boxed, canned, frozen, packaged and prepared foods. Make sure you check the ingredients on food labels before eating or drinking something.

Your provider may also recommend using a lactase product to prevent or lessen symptoms. Lactase products have the same enzyme that your small intestine makes and can help your body digest lactose.