Overview of IBS

Irritable bowel syndrome (IBS) is a pattern of symptoms that affects the intestines. The intestines, which are part of the digestive system, include the small intestine (also called the small bowel) and the large intestine (also called the large bowel, or colon).

In IBS, muscles that control the movement of food through the intestines do not function properly. Food is either pushed through too quickly (resulting in diarrhea) or too slowly (causing constipation). Symptoms, and the severity of symptoms, vary widely and often include cramping, bloating, and gas. Sometimes IBS symptoms come and go.

While irritable bowel syndrome seldom becomes serious, it causes discomfort and often keeps patients from participating in activities they enjoy doing. Changing eating habits, managing stress, and taking medications can help many patients deal with IBS.

Incidence and Prevalence of IBS

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), irritable bowel syndrome symptoms occur in about 20 percent of people in the United States. Up to 30 percent of people in the United States experience symptoms of IBS at some point during their lifetime. In about half of all cases, symptoms occur before the age of 35. Irritable bowel syndrome is approximately twice as common in women as in men.

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

Published: 28 Feb 2008

Last Modified: 22 Sep 2015