Causes and Risk Factors for Inflammatory Bowel Disease

The cause for inflammatory bowel disease is unknown. IBD may be caused by an immune system response that is related to a combination of genetic (hereditary), environmental, and infectious (e.g., viral, bacterial) risk factors.

In patients who have IBD, a genetic abnormality may cause the immune system to overreact to bacteria, a virus, or an environmental factor, resulting in chronic inflammation in the GI tract.

Environmental risk factors for inflammatory bowel disease may include the following:

  • Diet
  • High stress levels
  • Lack of exercise (sedentary lifestyle)
  • Smoking

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 28 Feb 2008

Last Modified: 22 Sep 2015