目的　探讨慢传输型便秘 (STC)的发生机理。方法　建立大鼠“泻剂结肠”模型 ,并测定其结肠的肌电生理活动变化。结果　“泻剂结肠”大鼠的结肠慢波频率减慢 ,振幅降低 ;餐后峰电位发放明显少于正常对照组且持续时间短 ,表明胃结肠反射明显减弱。结论　该研究结果提示 ,长期服用接触性泻剂对结肠肠神经系统有损害作用 ,这在STC的发生机理中可能具有重要意义 Objective To investigate the mechanism of slow transit constipation (STC). Methods The model of “cathartic colon” was established in rats and the change of myoelectric activity in the colon was measured. Results The colon slow wave frequency and amplitude of “laxative colon” rats were slowed down; the postprandial peak potentials were significantly less than those of the normal control group and the duration was short, which showed that the colon and colon reflexes were obviously weakened. Conclusions The results of this study suggest that long-term use of contact laxatives has a detrimental effect on the colonic nervous system, which may be of importance in the pathogenesis of STC