pathogenesis

Last reviewed 04/2022

The exact cause of the irritable bowel syndrome (IBS) is unknown and it is believed to be multifactorial in origin.

There are abnormalities in the muscular tone of the GI tract in these patients, but a low fibre diet also plays a part in the development of the condition. Colonic motility studies of patients with this condition have shown abnormal rises in intraluminal pressure and disordered peristalis, resulting in non-propulsive, segmenting contractions. Thus the small volume of stool (because of low residual fibre) becomes excessively dehydrated and fragmented so producing the rabbit dropping stools often complained of by these patients.

Recent research suggests that IBS may develop as a consequence of bacterial gastroenteritis.

The following factors may have a role in the pathogenesis of the IBS:

  • genetics - there may be a familial form
  • psychological factors