Irritable bowel syndrome (IBS)--definition and pathophysiology.

The article presents some individual perceptions of the nature of the disease we call the Irritable Bowel Syndrome (IBS), and attempts to rationalise the variable presenting features, the influence of the psyche and the lack of pathological or biochemical markers. Among the topics discussed include the existence of recognisable subsets of the disease, the influence of mental stress, and the pathophysiology of the presenting symptoms. My impression is that IBS is a condition, in which the gut is hypersensitive and hyper-reactive to mechanical and chemical stimuli and as such, can be compared with asthma in the respiratory system. This hyper-reactivity could be caused by increased mucosal permeability, increased numbers and/or responses of effector cells such as mast cells or enterochromaffin cells, and enhancement of intrinsic nerve reflexes by increased activity of efferent vagal fibres.