Relationship of underlying abnormalities in rectal sensitivity and compliance to distension with symptoms in irritable bowel syndrome.

BACKGROUND/AIMS: Abnormalities in rectal physiology play an important role in the genesis of symptoms in irritable bowel syndrome (IBS). However, their relationship to symptoms is unclear. Our aim was to investigate the association of abnormalities in rectal sensitivity and compliance to specific symptoms in IBS.

METHODS

Fifty-six IBS patients and 14 healthy controls participated in this study. The intensities of individual IBS symptoms in the past 4 weeks were scored on a graded 5-point Likert scale. Using a barostat, isobaric rectal distensions were performed before and after a meal.

RESULTS

Rectal hypersensitivity and hypocompliance in the fasting state were observed in 68 and 52% of IBS patients, respectively. Postprandial hypersensitivity of the rectum was significantly more prevalent in the diarrhea-predominant IBS (D-IBS) group compared to the constipation-predominant IBS (C-IBS) group. The D-IBS group showed a significant postprandial decrease in rectal compliance, but the C-IBS group did not. A significant correlation was observed between a sense of incomplete evacuation and increased bowel movements with postprandial rectal hypersensitivity or hypocompliance.

CONCLUSION

A sense of incomplete evacuation and increased bowel movements are related to postprandial abnormalities in rectal sensitivity and compliance to distension. The other IBS symptoms do not seem to predict such abnormalities.