结肠黑变病 (ｍｅｌａｎｏｓｉｓｃｏｌｉ,ＭＣ)是一种以结肠粘膜色素沉着为特征的非炎症性肠病 ,以前国外报道较多。随着便秘发病率的增加和肠镜诊断水平的提高 ,ＭＣ的发病率在国内呈明显的上升趋势。1　病因和发病机制便秘和长期口服泻药是目前被大多数学者所公认的引起ＭＣ Colitis melanosis (MC) is a non-inflammatory bowel disease characterized by colonic mucosal pigmentation, which was previously reported abroad. With the increasing incidence of constipation and colonoscopy diagnosis, the incidence of MC in the country showed a clear upward trend. 1 etiology and pathogenesis Constipation and long-term oral laxatives are currently recognized by most scholars cause MC