分析肛门指检及结肠镜检中低位直肠息肉的漏诊率及漏诊息肉特征，探讨结肠镜检结合肛门指检的重要性。

收集2012年9月至2013年5月在体检中心先后接受肛门指检及结肠镜检的244例受检者，分别对两种方法检查低位直肠息肉的漏诊情况进行分析。

89例发现直肠息肉并切除息肉143个。65例在距离肛门<7 cm肠段发现息肉94个，其中15例肛门指检漏诊息肉23个，29例结肠镜检漏诊息肉38个，结肠镜检的漏诊率高于肛门指检（24.5% vs 40.4%，χ²=5.460，P=0.019）。小息肉、平坦型息肉容易被漏诊；多发性息肉患者漏诊率较高；初级医师的息肉漏诊率明显高于有经验医师；肛门指检时间<2 min者的漏诊率高于≥2 min者；结肠镜检操作时间<35 min者的漏诊率高于≥35 min者；结肠镜检距离肛门≤3 cm的息肉的漏诊率明显高于肛门指检，差异均有统计学意义（P<0.05）。

结肠镜检和肛门指检均存在漏诊息肉的可能，息肉漏诊与息肉大小、形态、数目、病理以及操作医师、检查时间密切相关。结肠镜检查结合肛门指检，能降低低位直肠息肉的漏诊率。

To analyze the rates of missed diagnosis of digital rectal examination and colonoscopy and to explore the importance of colonoscopy combining digital rectal examination in patients with low rectal polyps.

Two hundred and forty-four patients receiving colonoscopy and digital rectal examination at the same time were retrospectively evaluated. The differences of missed diagnosis between the two methods were assessed by the Chi-square test.

One hundred and forty-three polyps in 89 patients were diagnosed and resected in our hospital. The mean polyp diameter was (0.59±0.35) cm. Ninty-four polyps in 65 patients were found located less than 7 cm to anus. Among them, 23 polyps in 15 patients were missed diagnosis with digital rectal examination, and the missed diagnosis rate was 24.5%; 38 polyps in 29 patients were with colonoscopy, the missed diagnosis rate was 40.4%. The rate of missed diagnosis by digital rectal examination was lower than colonoscopy, χ²=5.460, P=0.019. According to subgroup analyses, small polyps, flat polyps and multiple polyps tended to be missed diagnosis. The rate of missed diagnosis of colonoscopy operated by junior endoscopists was significantly higher than that operated by experienced endoscopists. The missed rate of digital rectal examination for <2 minutes was significantly higher than that for ≥2 minutes. The missed rate of colonoscopy operated for <35 minutes was significantly higher than that operated for ≥35 minutes. The rate of missed diagnosis of colonoscopy was significantly higher than digital rectal examination in examining polyps located<3 cm from anus. All the above differences were statistically significant, P<0.05.

Both colonoscopy and digital rectal examination may result in missed polyps. The rate of missed diagnosis is associated with polyp size, shape, number, pathology, operating physician, and the time of examination. Using colonoscopy combined digital rectal examination can reduce the missed diagnosis rate of low rectal polyps.