Overview of IBD

Inflammatory bowel disease (IBD) is a group of chronic conditions characterized by inflammation (i.e., pain, redness, and swelling) in the gastrointestinal (GI) tract, or digestive system. IBD can affect the small intestine, also called the small bowel, and the large intestine, also called the large bowel or colon. In some forms of inflammatory bowel disease, ulcers (sores or lesions) develop in the lining of the intestines.

The most common types of inflammatory bowel disease are ulcerative colitis and Crohn's disease. Ulcerative colitis affects the colon and Crohn's disease usually affects the small bowel or the colon. Other types of IBD include the following:

  • Enteritis (inflammation of the lining of the small intestine)
  • Ileitis (inflammation of the lower part of the small intestine)
  • Proctitis (inflammation of the lower part of the colon; i.e., the rectum and anus)

Inflammatory bowel disease is a chronic (long-lasting) condition. Over the course of the disease, periods of worsening symptoms (called exacerbations) and periods of improving symptoms (called remissions) are common.

Incidence and Prevalence of IBD

Inflammatory bowel disease is more common in developed areas of the world, such as the United States, Canada, and Western Europe. According to the U.S. Department of Health and Human Services, IBD affects about 1 million people in the United States, and approximately 30,000 people are diagnosed with the condition each year.

Inflammatory bowel disease affects men and women about equally, usually between the ages of 15 and 35. The condition often runs in families, and as many as 30 percent of all patients who have IBD also have a family member with the disease.

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

Published: 28 Feb 2008

Last Modified: 22 Sep 2015