There are many causes of bowel cancer, but the main ones are family genetic factors and long-term patients who eat high-protein and high-fat food, as well as long-term patients who lack crude fiber and green food. 1. Family genetic factors: 25% of bowel cancer occurs in families with a history of bowel cancer, and most members of some families are prone to polyps, and if left to develop, 25% of polyps will become cancer. Therefore, elderly people over 50 years old should have regular colonoscopy and fecal occult blood test. 2.Patients who often eat greasy food, spicy and stimulating food, fine food, irregular life, less vegetables and fruits, especially those who are often constipated, those who are obese and do not like exercise, and those who are lack of trace elements are risk factors for the development of intestinal cancer. 3. Smoking and alcohol consumption are also one of the risk factors for the development of colon cancer after many epidemiological surveys. Therefore, the causes of colon cancer are mainly the above aspects. If you eat less junk food, eat more fruits and vegetables, live a regular life, keep your bowels open, keep your mood happy and do not get angry, colon cancer can be prevented, and if there is chronic inflammation of intestine or polyps, early detection and early treatment are needed to repair the damaged intestinal mucosa so that the disease can be cured as soon as possible.