Causes of Inflammatory Bowel Disease

Reviewed by Nayana Ambardekar, MD on July 28, 2019

The cause of the inflammatory bowel diseases (IBD), ulcerative colitis, and Crohn's disease, is not known. Studies suggest they are caused by a combination of things, including genes, environmental factors, and problems with the immune system.

There is strong evidence to suggest a genetic basis for IBD, including:

  • Family history: As many as 20% of people with IBD have a family history of it.
  • Race and ethnicity: IBD is more common in white people. It's also more common in Jews, especially Ashkenazi Jews.

Inflammatory Bowel Disease Genes

In 2006, the first gene associated with Crohn's disease, the NOD2 gene, was identified. Since then, researchers have uncovered over 200 related genomic regions for IBD.

Finding a genetic link would help scientists understand the changes that lead to IBD, and help them improve treatments. A genetic link could also lead to a test for IBD.

WebMD Medical Reference



National Digestive Diseases Information Clearinghouse. 

Mayo Clinic. 

University of Maryland Medical Center. 

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