Outcome Analyses of 15,189 Screenings Via Colonoscopy.

Purpose: This study investigated the detection rates of common colorectal diseases during colonoscopy procedures to provide reference for clinical diagnoses in China. Methods: A total of 15,189 participants, who underwent total colonoscopy, were studied. We analyzed the detection rates of common colorectal diseases in different sex, age, and decade groups. Results: The most common indication for colonoscopy is abdominal pain followed by change in bowel habits. Among the 15,189 participants, 5658 cases (37.25%) were normal. The most common positive finding was colorectal polyp (27.32%) followed by nonspecific colitis (12.06%), colorectal cancer (CRC) (7.71%), and ulcerative colitis (4.64%). The frequencies of polyp (31.56% vs. 21.99%; P=0.000) and CRC (8.28% vs. 7.00%; P=0.004) were higher in males than in females. By contrast, ischemic colitis (0.08% vs. 0.31%; P=0.001) and melanosis coli (1.15% vs. 1.87%; P=0.000) were more seen in females than in males. In addition, the detection rates for CRC (2.42% vs. 7.18% vs. 16.67%; P=0.000), colorectal polyp (17.65% vs. 32.27% vs. 34.73%; P=0.000), ischemic colitis (0.09% vs. 0.19% vs. 0.32%; P=0.033), and melanosis coli (0.71% vs. 1.09% vs. 3.21%; P=0.000) increased with age. Conclusions: The frequent positive findings were colorectal polyp, nonspecific colitis, and CRC. Patients showing alarming symptoms definitely require colonoscopy. The detection rates for colorectal polyp and melanosis coli were significantly higher in the later decade, so we should focus on these deseases.