• Home

Home > Medical Reference > Encyclopedia (English)

Toggle: English / Spanish

Crohn's disease

• Overview
• Symptoms
• Treatment

Definition:

Crohn's disease is a form of inflammatory bowel disease (IBD), which involves ongoing (chronic) inflammation of the gastrointestinal tract. Crohn's-related inflammation usually affects the intestines, but may occur anywhere from the mouth to the anus (the end of the rectum).

See also: Ulcerative colitis

Alternative Names:

Inflammatory bowel disease - Crohn's disease; Regional enteritis; Ileitis; Granulomatous ileocolitis

Causes, incidence, and risk factors:

While the exact chain of events that lead to Crohn's disease is unknown, the condition is linked to a problem with the body's immune system response. Normally the immune system helps protect the body from harmful substances. But in patients with Crohn's disease and other types of inflammatory bowel disease (IBD), the immune system can't tell the difference between good substances and foreign invaders. The result is an overactive immune response that leads to chronic inflammation. This is called an autoimmune disorder.

There are five different types of Crohn's disease:

• Ileocolitis is the most common form. It affects the lowest part of the small intestine (ileum) and the large intestine (colon).
• Ileitis affects the ileum.
• Gastroduodenal Crohn's disease causes inflammation in the stomach and first part of the small intestine, called the duodenum.
• Jejunoileitis causes spotty patches of inflammation in the top half of the small intestine (jejunum).
• Crohn's (granulomatous) colitis only affects the large intestine.

A person's genes and environmental factors seem to play a role in the development of Crohn's disease.

The inflammation related to Crohn's disease frequently occurs at the end of the small intestine that joins the large intestine, but it may occur in any area of the digestive tract. There can be healthy patches of tissue in between diseases areas. The ongoing inflammation causes the intestinal wall to become thick.

The disease may occur at any age, but it usually occurs in persons between ages 15 and 35. Risk factors include a family history of Crohn's disease, Jewish ancestry, and smoking.

References:

US Food and Drug Administration. FDA Approves New Treatment For Crohn's Disease . Rockville, MD: National Press Office; February 27, 2007: Report P07-30.

Sandborn WJ, Hanauer SB, Rutgeerts PJ, et al. Adalimumab for Maintenance Treatment of Crohn's Disease: Results of the CLASSIC II Trial. Gut . 2007 Feb 13 [Epub ahead of print].

Hawk ET, Levin B. Colorectal cancer prevention. J Clin Oncol. 2005;23:378-388.

• Review Date: 3/6/2007
• Reviewed By: Updated by: A.D.A.M. Editorial Team: Greg Juhn, M.T.P.W., David R. Eltz, Kelli A. Stacy. Previously reviewed by Jenifer K. Lehrer, MD, Department of Gastroenterology, Frankford-TorresdaleHospital, Jefferson Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network.(2006)

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.