what causes irritable bowel syndrome
Irritable bowel syndrome. 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). 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.