Objective To study the clinical value of colonscopy in diagnosis of colorectal tumuor and the value of colonscopic polypectomy in reducing the incidence of colorectal cancer.

• 目的评价全结肠镜对大肠腺瘤性息肉及大肠癌的诊断价值以及大肠腺瘤性息肉摘除术对预防大肠癌发生的作用。