Recently, the small intestine has become the focus of investigation as a potential site of dysmotility in the irritable bowel syndrome (IBS). A number of motor abnormalities have been defined in some studies, and include 'clustered' contractions, exaggerated post-prandial motor response and disturbances in intestinal transit. The significance of these findings remains unclear. The interpretation of available studies is complicated by differences in subject selection, the direct influence of certain symptoms, such as diarrhoea and constipation, and the interference of compounding factors, such as stress and psychopathology. Dysmotility could also reflect autonomic dysfunction, disturbed CNS control and the response to heightened visceral sensation or central perception. While motor abnormalities may not explain all symptoms in IBS, sensorimotor interactions may be important in symptom pathogenesis and deserve further study.
