The differentiation between rectal polyps and rectal cancer can be made from the following aspects: First, clinical symptoms, rectal polyps usually have no symptoms or only mild symptoms such as abdominal pain and diarrhea, while rectal cancer will all show obvious symptoms such as abdominal pain, blood in stool and thinning of stool. Polyps grow slowly and the symptoms progress slowly, and the clinical symptoms are typical benign process, while cancer grows rapidly and the symptoms develop quickly, and the clinical symptoms have obvious malignant characteristics. Second, imaging examination, polyps present obvious benign features on CT, MRI and other imaging films, i.e. regular morphology, clear demarcation, and unobvious reinforcement after enhancement scan, while cancer is obvious malignant signs, irregular morphology is lobulated, unclear demarcation with surrounding tissues, and obvious uneven reinforcement after enhancement. Colonoscopy can directly observe the characteristics of the masses. Rectal polyps have regular shape, smooth surface and do not bleed easily when touched, while rectal cancer masses have irregular shape and bleed easily when touched, and colonoscopy can distinguish polyps and cancer very accurately by taking biopsy for pathological examination.