Crohn’s Disease vs. Lactose Intolerance: Similarities and Differences Explained

Medically Reviewed By Saurabh Sethi, M.D., MPH

Crohn’s disease and lactose intolerance can cause some of the same symptoms, and people with Crohn’s are more likely to be lactose intolerant. However, there are ways for the person affected and their doctor to tell the difference. Crohn’s disease is an autoimmune disorder that can inflame any part of the gastrointestinal (GI) tract, from the mouth to the anus. When lactose intolerant, your body has trouble digesting lactose, a sugar in milk and milk products.

This article discusses how Crohn’s disease and lactose intolerance are alike and different.

Causes

A person looking at cheese in a grocery store
Photography by ShotShare/Getty Images

The causes of these two conditions are different, though people with Crohn’s disease may also have lactose intolerance. A large 2020 study found that people with inflammatory bowel disease (IBD) — including Crohn’s disease — are more than 2.5 times as likely as people without IBD to have lactose intolerance.

Crohn’s disease

The exact cause of Crohn’s disease isn’t fully understood, but it involves an autoimmune reaction in which the body attacks its tissues. This may be due to Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source genetic and environmental factors like infections or medications.

Lactose intolerance

People who cannot digest lactose have low levels of the enzyme lactase, which is found in the small intestine. Lactase breaks down lactose into digestible sugars. Undigested lactose ferments and leads to digestive symptoms.

Crohn’s disease can lead Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source to lactase deficiency by damaging the inner lining of the intestinal tract, causing lactose intolerance.

Signs and symptoms

There are similarities in the signs and symptoms of Crohn’s disease and lactose intolerance, but there are also some notable differences.

Crohn’s disease

People with Crohn’s disease may experience:

Crohn’s disease may also cause Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source systemic signs and symptoms like fever or fatigue and extraintestinal signs like red eyes or bumps under the skin.

Learn more about 6 symptoms to never ignore if you have Crohn’s disease.

Lactose intolerance

People with lactose intolerance may experience GI signs and symptoms like:

Learn more about lactose intolerance symptoms.

Diagnosis

Doctors may perform a physical exam for both conditions, but further tests for Crohn’s disease and lactose intolerance are different.

Crohn’s disease

Doctors can diagnose Crohn’s disease using many methods. They can press on your abdomen to see whether it’s bloated or painful, and listen to your abdomen with a stethoscope.

If Crohn’s disease is a possibility, doctors may recommend an endoscopy, allowing them to conduct an internal examination while you’re sedated. They can examine the GI tract using a narrow tube with a small camera. Depending on your symptoms, the endoscopy may be of the colon or upper GI tract.

Your doctor may also order Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source imaging studies, such as CT or MRI scans, and blood or stool tests.

Lactose intolerance

Tests to diagnose lactose intolerance include a physical to assess bloating, pain, and intestinal sounds. To confirm a diagnosis, a hydrogen breath test can determine whether your system cannot digest lactose properly. Undigested lactose increases the amount of hydrogen in your breath.

A hydrogen breath test is simple. After drinking a liquid containing lactose, you breathe periodically into an instrument that measures the amount of hydrogen you exhale.

Treatments

The treatments for Crohn’s disease and lactose intolerance are different.

Crohn’s disease

There are many medications to treat Crohn’s disease, including:

  • aminosalicylates, which can help manage inflammation 
  • corticosteroids, which can be used for short-term inflammation relief
  • immunomodulators, which reduce immune system activity
  • biologics, which work against proteins that contribute to inflammation

Learn more about 10 medications doctors commonly prescribe for Crohn’s disease.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), bowel rest can also allow the GI tract to heal. This involves drinking special liquids for your meals. In severe cases, you may receive your nutrition through a feeding tube or intravenous (IV) line, which is inserted into a vein.

Surgery may also be needed to treat complications like intestinal obstructions or bleeding.

Learn more about treatment options for Crohn’s disease.

Lactose intolerance

Lactose intolerance can be managed with pills or liquids that contain lactase. If you’re pregnant or nursing, check with your doctor before taking these supplements.

You can also avoid foods with lactose. Because these foods contain many essential nutrients, you may need vitamin D or calcium supplements.

Depending on the cause of lactose intolerance, other treatments may be needed.

Summary

Crohn’s disease and lactose intolerance can cause diarrhea and abdominal pain. However, Crohn’s disease may also lead to signs and symptoms outside the GI tract, such as fever, red eyes, or bumps under the skin.

Crohn’s disease can cause lactose intolerance, so it’s essential to contact your doctor for a diagnosis of either condition.

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Medical Reviewer: Saurabh Sethi, M.D., MPH
Last Review Date: 2023 Aug 18
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