Rectal cancer can be screened by colonoscopy, rectal fingerprinting and pathological biopsy. 1. Colonoscopy: The most direct way to check rectal cancer is colonoscopy, because some rectal cancer patients will have changes in bowel habit, for example, they used to have regular bowel movement, but after suffering from rectal cancer, the number of times of bowel movement will obviously increase, the number of times of bowel movement will be about 5~6 times a day, and they will have the feeling of incomplete defecation, unshapely bowel movement, and feeling of falling down from the anus. 2. Rectal finger test: when doing examination, the doctor will first do rectal finger test, which is to touch the anus and rectum with fingers. If it is a low rectal tumor, it can be judged basically by rectal finger test, but it needs further colonoscopy for definite diagnosis. 3. Pathological biopsy: when doing colonoscopy, if suspicious or enlarged tissues are found, it is also necessary to take local pathological tissues for biopsy, and after taking pathological biopsy, the diagnosis will be confirmed. There are many ways to screen rectal cancer, and patients can also combine with their physical condition and choose suitable items for diagnosis under doctors’ advice.