1.After 40 years old, we should remove polyps in time People over 40 years old should do colonoscopy and anoscopy regularly, so that polyps can be detected and removed early to avoid cancerous changes. Colonoscopy can not only detect early bowel cancer, but also distinguish the nature and size of intestinal polyps, which can greatly reduce the chance of cancerous changes in patients. Moreover, the cure rate can reach about 90% after detecting early bowel cancer. Therefore, it is recommended that people over 40 years old should have a colonoscopy. 2. Early detection and early treatment is the key to reduce mortality rate If detected early, early rectal cancer treatment is very effective, with 5-year survival rate reaching 90%. When it is in advanced stage, the cancer cells will leave the thin-walled tissues of colon, rectum and small intestine and enter the blood stream directly, which can spread rapidly in the body and the treatment effect will be affected. 3. Do a good job in the three-level prevention of colorectal cancer: primary prevention, etiological prevention and lifestyle change; secondary prevention focusing on screening, census, early diagnosis and early treatment of precancerous lesions; and tertiary prevention, i.e. clinical treatment, focusing on standardized multidisciplinary comprehensive treatment by choosing reasonable treatment plans. 4. Genetic factors are important Research has found that genetic factors play an important role in colorectal cancer. Among the family members of colorectal cancer patients, the incidence rate of colorectal cancer is 3-4 times higher than that of the general population, and the family history of colorectal cancer is a high-risk factor for colorectal cancer. About one-third of colorectal cancers are genetically related, with familial adenomatous polyposis and hereditary nonpolyposis occurring as the most common hereditary colorectal cancers.