Objective: To investigate the detection rate of colorectal adenoma and gastric polyps in the asymptomatic population with the age of 40 to 59 years and to explore whether the patients with gastric polyps were the new target population for the colorectal cancer (CRC) screening. Methods: A total of 11 918 subjects of 40 to 59 years (5 616 males and 6 302 females) with the average risk of CRC were included during January 2015 to December 2018 at the endoscopy center of Ruijin Hospital, Shanghai Jiao Tong University School of Medicine. All the subjects underwent colonoscopy and volunteered to undergo esophagogastroduodenoscopy (EGD), and were grouped by the age interval of 5 years and gender. The patients with gastric polyp (GP group) and with EGD negative results (EGD negative group) were enrolled based on the pathological biopsy results, and the clinical characteristics and detection rate of colorectal polyp, adenoma and advanced adenoma were compared between two groups. Results: The overall detection rate of colorectal poly,adenoma,and advanced adenoma were 10.7%, 15.4%, and 3.6%, respectively. For the male subjects, the detection rates of colorectal polys, adenoma, and advanced adenoma were 14.0%, 19.8% and 4.7%, respectively,while for the female subjects, the corresponding rates were 7.6%, 11.4% and 2.7%. The detection rate of colorectal adenoma was significantly higher in the GP group than in the EGD negative group (16.7% vs 11.7%) (P<0.001). In the GP group, the detection rate of colorectal adenoma in the males of 45 to 49 years was significantly higher than the males of 40 to 44 years (26.7%, 28/105 vs. 14.6%, 15/103) (P=0.031), but was similar to the rates in the males of 50 to 54 years (18.8%, 29/154) and 55 to 59 years (26.3%, 41/156). However, the colorectal adenomas were less common in women of 40 to 44 years(7.6%, 10/132) and 45 to 49 years (11.2%, 21/187). Conclusions: The detection rate of asymptomatic colorectal adenoma in the population of 40 to 59 years was 3.6%. Male patients of 45 to 49 years having gastric polys with the average risk of CRC are a new target population for colonoscopy screening.