Rectal cancer self-test: 1, daily high protein, high fat, low fiber diet. 2.Have rectal polyps. 3.Chronic inflammation of the colon and rectum. 4.Someone in the family has “familial colon polyp disease”. 5.Blood mixed with stool, not just blood on the surface of the stool. 6.Changes in bowel habits, such as: once a day to multiple times a day; frequent constipation, constipation for no reason to improve; habitual defecation of formed stools, for no reason to defecate unformed stools; stool shape changes; often want to defecate, but to the toilet but no stool to solve; stool mucus more. 7, left lower abdominal pain, intermittent vague pain, to the late stage of persistent pain, or paroxysmal aggravation. 8.Persistent pain in the anus. If you have the above symptoms, it is recommended to visit the hospital for examination to exclude rectal cancer.