The irritable bowel syndrome (IBS) has many other names including functional indigestion, mucus colitis, nervous dyspepsia and spastic colon. It causes abnormal spasms of the muscles in the wall of the large intestine.
The gut is a long tube with bands of muscle running along and around it. The movement of the food from one end to the other is the result of rhythmic contractions of these muscles, which send waves and ripples along the gut to push food along. Nutrients are removed from the gut, and only non-absorbable fibre and roughage remains to be passed out through the anus. Up to 20% of adults have symptoms of the irritable bowel syndrome at some time, but only a fraction of these people require medical treatment.
If the diet consists of large amounts of refined foods with little fibre content, the bulk of the faeces is reduced. When the muscles in the large intestine contract, they may have very little to push along, and this may lead to spasms of the gut. People with tense personalities or continuing stress will find that their intestine acts more rapidly than normal due to over stimulation. Over a number of years, the combination of a low-fibre diet, anxiety, stress and hereditary factors may lead to the development of this syndrome which is more common in women.
Abdominal pain occurs due to intense spasms of the bowel muscle, and patients experience alternating constipation and diarrhoea, excess passage of wind by mouth and anus, nausea, loss of appetite and mucus on the stools. Once established, the pattern may be very difficult to break, as the symptoms cause further anxiety in the victim, which in turn exacerbates the original symptoms.