The Rectal Perception in Patients with Constipation-predominant Irritable Bowel Syndrome and Functional Constipation

Yang, Jae Hoon; Lee, Joon Seong; Hong, Su Jin; Im, Hee Hyuk; Hwang, Kyung Ran; Kim, Hyun Jung; Lee, Sang Ho; Koh, Bong Min; Jung, In Seop; Ryu, Chang Beom; Kim, Jin Oh; Cho, Joo Young; Lee, Moon Sung; Shim, Chan Sup; Kim, Boo Sung

Abstract

BACKGROUND/AIMS
The differential diagnosis of constipation-predominant irritable bowel syndrome (IBS-C) and functional constipation (FC) is difficult in many cases, even though the suggested pathophysiologies are quite different. The presence of visceral hypersensitivity, which is frequent in diarrhea-predominant irritable bowel syndrome, is still controversial in IBS-C. The aim of this study was to evaluate the differences in rectal visceral sensitivity to rectal distension in patients with IBS-C and FC.
METHODS
In thirty eight patients with FC and 31 patients with IBS-C, as accessed by the Rome II criteria, rectal visceral sensitivity and compliance were measured by a barostat examination. Pressure thresholds of the first sense, urgency, maximum tolerable volume and the sensitivity index percentage were compared in both group according to the gender.
RESULTS
for the female patients, the sensitivity index percentage of the IBS-C was significantly lower than that of FC (p<0.05). for the male patients, the first sense threshold pressure was significantly lower in the IBS-C patients than in the FC patients, (p<0.05).
CONCLUSIONS
The patients with IBS-C showed more rectal visceral hypersensitivity compared with the FC patients irrespective of the gender. Male patients with IBS-C showed visceral hypersensitivity to low-grade stimuli; in contrast, the female patients with IBS-C showed hypersensitivity to high-grade stimuli, suggesting a differential pathophysiologic mechanism of visceral hypersensitivity in the different gender patients with IBS-C.