大肠癌将超过胃癌成为引起死亡的主要胃肠道肿瘤[1]。早期诊治可以明显改善大肠癌的预后,5年生存率可达95%以上。但是,早期大肠癌和患有癌前病变的患者通常无任何症状。如何将这些患者筛查出来并发现病灶及时处理已成为医学界亟待解决的重要问题。消化内镜是解决这一问题的重要 Colorectal cancer will overtake gastric cancer as the leading cause of death of the gastrointestinal cancer [1]. Early diagnosis and treatment can significantly improve the prognosis of colorectal cancer, 5-year survival rate of up to 95%. However, early colorectal cancer and patients with precancerous lesions usually have no symptoms. How to screen out these patients and find the timely treatment of lesions has become an urgent medical problem to be solved. Digestive endoscopy is an important part of solving this problem