Abdominal Symptoms Are Not Related to Anorectal Function in the Irritable Bowel Syndrome

Background: The pathophysiologic significance of altered intestinal motility and perception in irritable bowel syndrome (IBS) is unclear, as a consistent association with abdominal symptoms has not been proved. Our aim was to investigate the association between abdominal symptoms and anorectal function in IBS. Methods: Fifty-two patients recorded their symptoms daily for 1 week. At the end of the week anorectal function was investigated by manovolumetry before and after a standardized fatty meal. Cluster anlysis of daily recorded symptoms and both pre- and postprandial manovolumetric data was performed to identify symptom and physiologic subgroups. Results: Symptom subgroups did not differ with regard to anorectal function. Physiologic subgroups did not differ with regard to daily recorded symptoms. Postprandially, the thresholds eliciting maximal tolerable distention were decreased in 22 of the patients. This increase in rectal sensitivity was not related to symptoms and may have been caused by the preprandial anorectal measurement, since thresholds for maximal tolerable distention decreased significantly in nine patients retested without an intervening meal. Conclusions: Abdominal symptoms and anorectal function are not related in IBS.