Other names for IBS
These names are misleading because IBS is not limited to the colon.
Your bowel, or gut, extends from your stomach to your anus. It is made up of the small intestine and the large intestine. Their job is to process food from the stomach.
The normal bowel moves food along the intestines through muscular contractions, known as propulsion. There are also areas of hold-up, known as segmentation.
This combination of propulsion and segmentation is called peristalsis. You are completely unaware of it when it is working normally.
The control of peristalsis is complex. The best way to regard IBS is as a loss of coordination of these muscular contractions.
In addition, there is evidence that people with irritable bowel syndrome have increased sensitivity within the gut to external stimuli such as stress. This means IBS is often the outcome of a complex interaction between psychological and physical factors.
A disorder of the digestive system can affect the gut anywhere from the mouth to the anus, which accounts for the diversity of symptoms seen in IBS. Click for a list of IBS symptoms.