Abstract:Abstract: Objective To explore the application of colonoscopy screening in the health checkup of middle-aged and elderly people. Methods Collecting and collating the colonoscopy data of 11 547 middle-aged and elderly people who came for health check-up from January 2010 to January 2018, and the effect of colonoscopy on colorectal cancer screening in middle-aged and elderly people was analyzed. Results The positive screening rate of 11 547 middle-aged and elderly people was 16.77% (1 937/11 547), and the first and second participation rates of male patients were lower than that of females, but the overall positive rate of male patients in the first, second and primary screenings. All were higher than women, the difference was statistically significant (P < 0.05). There was no significant difference in the initial screening participation rate among the 45 ~ 55 group, 56 ~ 60 group, 61 ~ 65 group, 66 ~ 70 years old, but the initial screening participation rate of patients aged 71 ~ 75 years was significantly lower than that of other age groups. With the increase of age, the overall positive rate of the first, second and primary screening patients increased, the difference was statistically significant (P < 0.05). Patients with inflammation, common adenoma, non-adenomatous polyps as the main lesions, male patients with colorectal cancer, advanced adenoma, common adenoma, non-adenomatous polyps have higher rates of disease than female patients, melanosis and inflammatory lesions. The rate was lower than that of female patients, and the difference was statistically significant (P < 0.05). Patients in the 45 ~ 55 group and the 61 ~ 65 group were mainly inflammatory lesions, 56 ~ 60 group were mainly black syndrome, and 66 ~ 70 group and 71 ~ 75 group were mainly adenomas. Conclusion Colonoscopy screening can effectively detect intestinal lesions in the middle-aged and elderly population. Although the incidence of colorectal cancer increases with age, it should improve the colonoscopy compliance of the middle-aged and elderly population.