The possible causes of rectal swelling of one centimeter are: rectal polyps, rectal mucosal prolapse, rectal cancer, internal hemorrhoids and so on. 1. Rectal polyps: intestinal polyps refers to the intestinal lumen from the mucous membrane suggests convex to the intestinal lumen of the elevated lesions, there are many different types, such as inflammatory polyps, adenomatous polyps, hyperplastic polyps, etc. Among them, adenomatous polyps and polyposis have different malignant tendencies. There are many different types of polyps, such as inflammatory polyps, adenomatous polyps, hyperplastic polyps, etc. Among them, adenomatous polyps and polyposis have different degrees of malignant tendency. 2. Rectal mucous membrane prolapse: rectal mucous membrane prolapse is a set of rectal mucous membrane formed during defecation due to relaxation, which can easily cause anal canal wound blockage and cause defecation difficulty. 3. Rectal cancer: the bulging type of rectal cancer is mainly manifested as a swelling projecting into the intestinal cavity, and the surface can form erosion or ulcer, and the prognosis is usually better. 4. Internal hemorrhoids: internal hemorrhoids refer to the redundant organisms formed by the hypertrophy and displacement of the anal cushion located at the dentate line of the anal canal, which are prone to bleed during defecation, and sometimes can be prolapsed out of the anus. The discovery of rectal 1 cm swelling, it is recommended that the patient to the hospital in time, clear diagnosis and follow the doctor’s instructions to be treated accordingly.