便秘型肠易激综合征患者肛门直肠运动感觉功能及自主神经活性的变化

Investigation on the impaired rectal compliance and sympathetic activity in patients with constipation-predominant irritable bowel syndrome

目的研究便秘型肠易激综合征(C-IBS)患者肛门直肠感觉运动功能及自主神经活性变化,以探讨C-IBS的发病机制。方法用电子气压泵及液流灌注压力监测系统对28例C-IBS患者和15名对照组进行肛门直肠测压检查。对其中12例C-IBS患者和8例健康志愿者,通过HRV频域分析比较两组交感神经张力的变化。结果C-IBS患者的肛门内括约肌最大收缩压、最小抑制容量、直肠顺应性、初始感觉阈值、初次排便阈值、排便窘迫阈值、最大容量感觉阈值均明显低于对照组(P<0.05)。在C-IBS患者组及对照组中,P1/(P1+P2)在产生便意、排便窘迫、最大耐受时均显著高于基础静息状态(P<0.05);C-IBS患者组P1/(P1+P2)在基础静息、产生初始感觉、产生便意、排便窘迫时显著高于对照组(P<0.05)。结论C-IBS患者存在直肠感觉过敏和自主神经功能异常,直肠顺应性也显著低于对照组,可能是C-IBS的发病机制之一。

Objective To investigate rectal sensation, motility and the impaired sympathetic activity in patients with constipation-predominant irritable bowel syndrome （c-IBS）. Methods 28 patients with c-IBS and 15 healthy volunteers were involved in this study. Anorectal manometry and rectal visceral perception to balloon distention were measured by electric barostat and perfusion catheter manometer. In 12 of the 28 C-IBS patients and 8 of the healthy volunteers,the eletrocardiography was recorded and rectal visceral perception to balloon distention was measured ; the changes of sympathetic activity were compared be- tween the two groups by heart rate variability （HRV）. Results The maximal squeeze pressure, the minimal rectal distention volume that could induce the rectum-ano inhibition reflex,the rectal compliance, the thresholds of the first sensation volume, defecation volume, pain volume of rectum and rectal maximum tol- erable volume thresholds in patients with C-IBS were all significantly lower than those in healthy vohmteers （P 〈 O. 05）. In the two groups, while comparing with the baseline state,the sympathetic activity was significantly increased during the period of first sensation of defecation and urgency of defecation, and rectal maximum tolerable vohane thresholds were achieved（ P 〈 0. 05 ）. While comparing with the healthy volunteers group,the sympathetic activity in c-IBS group during the period of baseline state,first sensation of defecation and urgency of defecation were significantly higher than those in control group （ P 〈 O. 05 ）. Conclusion The decreased rectal compliance suggests the visceral hypersensitivity in c-IBS and may contribut to the mechanism of c-IBS symptoms. The normal resting pressure and resting pressure of internal anal sphincter suggest that the anal-rectal motility maybe not be the main reason for the symptoms in c-IBS. Patients with c-IBS showed higher sympathetic activity than healthy volunteers, which suggests that impaired sympathetic activity may contribute to the mechanism of c-IBS.