[Colonic motility in the irritable bowel syndrome]

Abstract

The importance of colonic motor disorders during the irritable bowel syndrome is recognized, but, paradoxically, their description has yet to be perfected. Among the fundamental questions that remain unanswered, three are of prime importance: a) are there one or more specific disturbances in basal colonic motility? b) can specific motor disorders be induced by certain situations, for instance, during stress? c) is there any real relationship between clinical symptoms and coexisting motor disorders? The answers to these questions are full of ambiguities; this may be explained by the difficulty with which methods of investigation are performed as well as the heterogeneous character of the disorders. Presently, recording colonic myoelectric activity over a 24 hour period or more might prove to be useful in increasing our knowledge on motor disorders. It is not at all certain that a specific basal abnormality exists and the results of the effects of stress vary according to the methods used. Segmental hyperactivity in painful constipation, abnormal colonic response to alimentation in the case of painful bloating, and propulsive hyperactivity with absence or decrease in the "sigmoid brake" during painless diarrhea have been noted on basal motor activity recordings during sleep and after meals. Myoelectric disorders, however, are seen in only two-thirds of patients with intestinal functional disorders. "Sensitivity", personality, or other disorders, and particularly, intestinal disorders, can contribute to explain the pathophysiology of "irritable bowels" in which the role of colonic disorders has yet to be shown.