What is irritable bowel syndrome?

Irritable bowel syndrome (IBS) is a common problem with the intestines. In people with IBS, the intestines squeeze too hard or not hard enough and cause food to move too quickly or too slowly through the intestines. IBS usually begins around age 20 and is more common in women.

IBS is also called functional bowel syndrome, irritable colon, spastic bowel and spastic colon. It's not the same as inflammatory bowel diseases like ulcerative colitis.