Irritable bowel syndrome (IBS) is a chronic (long-term) disorder that affects the digestive system. It causes abdominal pain, diarrhoea and constipation.
There are different types of IBS, depending on your main symptom. It's known by a variety of other names, including spastic colon, spastic colitis, mucous colitis, nervous diarrhoea, nervous colon and nervous or functional bowel.
However, some of these names misrepresent the condition. Colitis, for example, is an inflammation of the colon and this symptom isn't found in people with IBS.
The symptoms of IBS can fluctuate. There may be times when your symptoms are particularly troublesome and times when you experience no symptoms at all.