A positive S9 methylation test suggests further tests such as a colonoscopy to determine if you have colorectal cancer and the location of the lesion. The S9 (Septin9) gene is commonly used in colorectal cancer screening and has a relatively high overall sensitivity, which increases with the later the stage of colorectal cancer. When there is a positive S9 methylation test, one should go to the hospital in time to complete the relevant examinations to determine whether there is colorectal cancer, such as colonoscopy, etc., so as to avoid missing the diagnosis and delaying the condition. Patients with colorectal cancer usually have a family history of changes in bowel habits and stool characteristics, and those who have previously suffered from chronic inflammatory bowel disease and adenomatous polyps are at high risk.