The prevention of colon and rectal cancer is mainly to minimize cancer-causing factors, and people with high risk should be regularly screened for early detection and treatment. At present, the underlying causes of colon and rectal cancer are not fully understood, so effective prevention cannot be carried out yet, but it is still possible to reduce the incidence and detect cancer at an early stage if some of the following measures are indeed taken 1.Actively treat possible precancerous lesions, such as hemorrhoids, anal fistula, enteritis, etc. 2.Diversify the recipes, eat more fresh fruits and vegetables containing various vitamins, and keep the bowels open. 3.Observe your stool frequently and pay attention to any changes in bowel habits and stool properties. 4.People with change in stool habit, such as long-term rotten stool, pus stool and slop-like stool, should go to hospital for examination as soon as possible. 5.Participate in the tumor screening work carried out by the hospital, check the exfoliated cells in the stool, fecal occult blood test, carcinoembryonic antigen (CEA) level test, rectal finger examination, colon endoscopy or air-barium double imaging examination, which can enable early detection and early treatment.