RESUMO
Objective To investigate the missing rate of polypus with colonoscopy and correlation factors for missed diagnosis.Methods Data with colorectal polyps collected a second colonoscopy within 180 days after polyps were detected and removed on the initial colonoscopy in 186 patients between July 2009 and June 2013.The following factors were statistically analyzed,including lesionrelated factors (the lesion size,location,shape,number,and pathology),and non-lesion-related factors (intestinal cleanliness,colonoscopy post-set time,colonoscopy operator experience,and whether colonoscopy with sedation).Results Polypus missed diagnosis was found in 57 patients out of 186 recruited subjects (30.64％).A total of 76 polypus were missed out of 343 (22.16％) polypus detected by repeated colonoscopy.Flat small polyps were easily missed diagnosis (P ＜ 0.01).Polyps located at sigmoid,cecum and ascending colon,hepatic flexure,and splenic flexure were easily missed diagnosis (P ＜0.05).The rate of missed diagnosis was significantly increased in the condition of the low intestinal cleanliness,short colonoscopy post-set time,non-intravenous anesthesia,and beginner colonoscopy doctors (P ＜ 0.01).Conclusions A markedly missing rate of polyp existed on colonoscopy,and was closely related to the lesion-related factors (the lesion size,location,shape,number,and pathology) and the non-lesion-related factors (the intestinal cleanliness,colonoscopy post-set time,colonoscopy operator experience,and whether colonoscopy with sedation).