Abstract

Backgound/Aims: While colonoscopy is the gold standard diagnostic test for the detection of colorectal polyps (especially adenomas), it is also an imperfect method. We prospectively estimated the colonoscopic miss-rate of colorectal polyp and adenoma. Methods: We performed polypectomies in 603 out of 2,006 patients over age of 40 who underwent their first time colonoscopy between September 1999 and June 2001. A follow-up colonoscopy was performed within 60 days in 235 (53.4%) among 440 enrolled patients. Results: Seventy-three (31.0%) of 235 patients with polyps on initial colonoscopy were missed polyps and 37 (23.2%) of 159 patients with adenomas on initial colonoscopy were missed adenomas. As the number of polyps on the initial examination increased, the miss-rate increased significantly (p=0.01). The most frequent size of missed polyp was 3∼4 mm (55.5%, p=0.00) and the most frequent location was sigmoid colon (27.3%, p=0.00). Conclusion: It may be a fallacy to declare that all colorectal polyps are removed just after one session of colonoscopy. Examiners should make every effort to reduce the miss-rate of colorectal polyps during colonoscopy. (Korean J Gastrointest Endosc 2003;26:199⁣204)

• Keywords: Colorectal polyp, Colorectal adenoma, Colonoscopy, Miss-rate