Irritable bowel syndrome (IBS) is a disorder that leads to abdominal pain and bowel changes.
IBS is not the same as inflammatory bowel disease (IBD).
Spastic colon; Irritable colon; Mucous colitis; Spastic colitis
The reasons why IBS develops are not clear. It can occur after an infection of the intestines. This is called postinfectious IBS. There may also be other triggers, including stress.
The intestine is connected to the brain using hormone and nerve signals that go back and forth between the bowel and the brain. These signals affect bowel function and symptoms. The nerves can become more active during stress. This can cause the intestines to be more sensitive and contract more.
IBS can occur at any age. Often, it begins in the teen years or early adulthood. It is twice as common in women as in men.
About 1 in 6 people in the United States have symptoms of IBS. It is the most common intestinal problem that causes people to be referred to a bowel specialist (gastroenterologist).