Children's Hospital Colorado

Irritable Bowel Syndrome (IBS)

What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome, also known as IBS, is a disorder that leads to abdominal pain and cramping, changes in bowel movements and other symptoms.

What causes irritable bowel syndrome?

It is not clear why patients develop irritable bowel syndrome. Sometimes it occurs after an infection of the intestines; this is called post-infectious irritable bowel syndrome. There may also be other triggers. The intestine is connected to the brain by many nerves that carry signals back and forth between the bowel and brain. These signals affect bowel function and symptoms. They can change the color, consistency and frequency of bowel movements. The nerves can become more active during stress, causing the nerves to become more active, which then makes the intestines to be more sensitive and squeeze (contract) more.

Who gets irritable bowel syndrome?

Irritable bowel syndrome can occur at any age, but it often begins in the teen years or early adulthood. It is twice as common in women as in men. About one in six people in the U.S. have symptoms of irritable bowel syndrome. It is the most common intestinal problem that causes patients to be referred to a bowel specialist (gastroenterologist).