The rectal mucosa is divided into five layers, namely, mucosa, submucosa, muscularis propria, tunica albuginea and plasma membrane. 1. Mucosal layer: the mucosal layer can be divided into epithelial and lamina propria, of which the epithelial layer is a single layer of columnar epithelium in the juxtaposterior region of the rectum, and there is no keratinization at the dentate line of the complex flat epithelium; and the lamina propria is a columnar cell and a cup cell in the juxtaposterior region of the juxtaposterior region of the juxtaposterior region of the rectum, which contains a large number of intestinal glands, and also has many small veins at the dentate line. 2. Submucosa: The submucosa of the rectum is a loose connective tissue, which contains a large number of veins and small blood vessels. 3. Muscular layer: the rectal muscular layer is similar to the mucosal muscular layer, and it is also divided into two layers of smooth muscle, which are inner circular and outer longitudinal, and the smooth muscle walks to the dentate line and disappears. 4. outer membrane and plasma membrane: the outer membrane of rectal mucosa and plasma membrane is fibrous membrane, mainly composed of fibrous tissue. Rectal mucosa damage is likely to increase the possibility of inflammatory lesions, thus affecting the intestinal function of abdominal pain, abdominal distension and other symptoms, and in severe cases, may lead to loose stools, acute and severe, mucus, pus and blood stools and so on. If proctitis occurs, long-term untreated may evolve into chronic proctitis, it is recommended to go to the regular hospital anorectal department, for the cause of the active treatment, to avoid aggravation of the condition.