Irritable bowel syndrome (IBS) is a problem that affects the large intestine. It can cause abdominal cramping, bloating and a change in bowel habits. 

Although IBS can cause a great deal of discomfort, it does not harm the intestines. IBS is a common disorder and happens more often in women than men. No one knows the exact cause of IBS. There is no specific test for IBS. However, your doctor may run tests to be sure you don't have other diseases. These tests may include stool sampling tests, blood tests and x-rays. Your doctor may also do a test called a sigmoidoscopy or colonoscopy.

Most people diagnosed with IBS can control their symptoms with diet and stress management.

References

National Institute of Diabetes and Digestive and Kidney Diseases: http://www.nlm.nih.gov/medlineplus/irritablebowelsyndrome.html