Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein. Lactose intolerance is a problem that makes it hard to digest lactose. Lactose is a type of natural sugar found in milk and dairy products. This condition isn't the same thing as a food allergy to milk. When lactose moves through the large intestine (colon) without being properly digested, it can cause gas, belly pain, bloating, and diarrhea. Some people who have lactose intolerance can't eat or drink any milk products. Others can eat or drink small amounts of milk products or certain types of milk products without problems. Lactose intolerance occurs when the small intestine doesn't make enough of an enzyme called lactase. Your body needs lactase to break down, or digest, lactose. Sometimes the small intestine stops making lactase after a short-term illness, such as a stomach infection, or as part of a lifelong disease, such as cystic fibrosis. Symptoms of lactose intolerance can be mild to severe. Your symptoms may depend on how much lactase your body makes. Symptoms usually start 30 minutes to 2 hours after you eat or drink milk products. Symptoms may include: A doctor can usually tell if you have lactose intolerance by asking questions about your symptoms. You may be asked to avoid dairy products for a short time to see if your symptoms improve. If symptoms improve, you may be asked to add small amounts of milk products to see if your symptoms return. Sometimes doctors order tests to confirm the diagnosis. These simple tests check to see if you are digesting lactose normally. These two tests usually aren't done for babies or very young children. If you have lactose intolerance: Current as of: September 20, 2023 Author: Healthwise Staff Current as of: September 20, 2023 Author: Healthwise Staff Clinical Review Board This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use and Privacy Policy. Learn how we develop our content. To learn more about Healthwise, visit Healthwise.org. © 1995-2024 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.Topic Contents
Lactose Intolerance
Condition Basics
What is lactose intolerance?
What causes it?
What are the symptoms?
How is lactose intolerance diagnosed?
What can you do about lactose intolerance?
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Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein. Current as of: September 20, 2023 Author: Healthwise Staff Clinical Review BoardLactose Intolerance
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.