Rectal polyps from three years ago to now are not necessarily cancerous. Rectal polyp cancer is affected by many factors such as type of polyp, dietary habits, bowel habits, smoking, age, family history and so on, and the time of occurrence varies. 1. The types of rectal polyps can be seen as adenomas, hyperplastic polyps and inflammatory polyps. Adults are often adenomas, with a diameter greater than 2cm, about half of which are prone to cancer. Hyperplastic polyps, often hairy, the diameter of more than less than 5mm, for the non-tumor polyps. Inflammatory polyps, caused by inflammatory stimulation of intestinal epithelium, generally have no malignant tendency. 2. Dietary habits: excessive fat and protein intake, lack of dietary fiber and other bad dietary habits are high-risk factors for the occurrence of rectal cancer. Poor defecation habits, smoking, age, family history, etc. are all high risk factors for rectal cancer. For those who have rectal polyps, it is recommended to go to local hospitals regularly for rectal related examinations, such as rectal fingerprinting, colonoscopy, etc., to observe the changes in the nature of the polyps, so as to avoid any abnormalities that may be missed.