Crohn Disease

(CD; Regional Enteritis)


Crohns disease is long term inflammation and irritation in the digestive tract. It is a type of inflammatory bowel disease. Crohns disease can affect any of the tract from mouth to anus. It is more common in the end of the small intestine or beginning of large intestine. Crohns can have flare ups and periods of no symptoms called remission.

Small Intestine

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It is not clear what causes Crohns disease. Genes, the environment, and problems with the immune system may all play a role.

Risk Factors

The risk of Crohns disease is higher in those with:

  • Family members with Crohns
  • Tobacco use disorder
  • Low activity levels
  • Stress-related disorders
  • Regular use of medicine, such as antibiotics and nonsteroidal anti-inflammatory drugs
  • Infections of digestive system, such as salmonella or campylobacter gastroenteritis


Flare ups of Crohns disease may cause:

  • Diarrhea
  • Belly cramps and pain
  • Rectal bleeding
  • Weight loss
  • Weakness and lack of energy
  • Nausea
  • Fever
  • Mouth sores
  • Sores in the anal area


The doctor will ask about your symptoms and past health. A physical exam will be done. Blood and stool tests will be done to look for any problems and rule out other issues. Scopes can be done to look for areas of inflammation. This can be done with:

A sample of intestine may be removed with a scope for biopsy. The sample will be sent to a lab for testing.

Special dyes may also be used to help highlight the intestines in other image tests such as:


There is no cure. Flare up treatment will manage symptoms and try to avoid other problems from starting. Treatment may also be used during remission to prevent flare ups. The treatment plan can vary. Some step may include:

  • Medicines to help:
    • Reduce inflammation—may be short term for flare ups
    • Lower immune system response—may be long term medicines to help prevent flare up
    • Manage pain, diarrhea or nausea
  • Bowel rest for severe bout of inflammation—no food, only drinking nutritious drinks for a time.
  • Nutrition support—vitamins or supplements to improve nutrition during flare up.
  • Surgery—to removed damaged areas, improve severe symptoms, or treat complications of Crohns.

Other treatment may be needed to treat other problems caused by Crohns.


There are no known methods to prevent Crohns disease.


Crohn's & Colitis Foundation
National Institute of Diabetes and Digestive and Kidney Diseases


Crohn's and Colitis Canada


Crohn disease. Merck Manual Professional Version website. Available at:
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Accessed March 16, 2021.
Crohn disease in adults. EBSCO DynaMed website. Available at: Accessed March 16, 2021.
Crohn's disease. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: Accessed March 16, 2021.
Lichtenstein GR, Loftus EV, et al. ACG Clinical Guideline: Management of Crohn's Disease in Adults. Am J Gastroenterol. 2018 Apr;113(4):481-517.
What is Crohn's disease? Crohn's & Colitis Foundation website. Available at:
...(Click grey area to select URL)
Accessed March 16, 2021.
Last reviewed December 2020 by EBSCO Medical Review Board Daniel A. Ostrovsky, MD
Last Updated: 03/16/2021

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