The Clinical Validity of Symptom-based Subgrouping of Irritable Bowel Syndrome According to the Rectal Sensory and Motor Function

Lee, Kwang Jae; Meong, Bo Heon; Kim, Jin Hong; Hahm, Ki Baik; Cho, Sung Won

Abstract

BACKGROUND/AIMS
It is uncertain what difference exists in the rectal motor and sensory characteristics between the diarrhea-predominant (D-IBS) and constipation-predominant (C-IBS) IBS subgroups. Our aim was to investigate the differences in the compliance, sensitivity and postprandial response of the rectum between the D-IBS and C-IBS patients.
METHODS
Twenty-one D-IBS patients, sixteen C-IBS patients and fourteen healthy controls participated in this study. Using a barostat, sequential isobaric rectal distensions were performed, and then the postprandial change of the rectal tone was evaluated. Subsequently, the isobaric rectal distensions were repeated.
RESULTS
While no differences in rectal compliance and the prevalence of hypocompliant rectum between two subgroups were observed during the fasting period, the D-IBS patients exhibited lower rectal compliance and a higher prevalence of hypocompliant rectum in the postprandial period compared to the C-IBS patients. A significant postprandial decrease of rectal compliance was observed in the D-IBS patients, but not in the C-IBS patients. No differences were observed between the subgroups in the threshold pressures for discomfort or pain, the prevalence of hypersensitive rectum and the response of rectal sensitivity to a meal. The postprandial increase of the rectal tone was significantly lower in the C-IBS patients, as compared with D-IBS patients.
CONCLUSIONS
The symptom-based subgrouping of IBS is related to the responsiveness of rectal compliance and tone to a meal.