Inflammation of the rectal mucosa often caused by the treatment of cervical cancer or anorectal cancer with radiation therapy is called radiation proctitis. The main reason for the occurrence of radiation proctitis is caused by the patient’s increased sensitivity to radiation during radiation therapy, which is related to the size of radiation dose. In the initial stage, the rectal mucosa is red, swollen, and congested, or there are small bleeding spots and gray exudate on the mucosal surface. After several months or years, an ulcer is formed, usually only one ulcer, shallow and rounded, with an unclean bottom and slow healing. When the necrotic tissue is shed, it can bleed, the perirectal tissue hardens, the rectal wall thickens, the mucosa atrophies and turns yellow, and a lot of mucus flows from the rectum and vagina, sometimes forming a rectovaginal fistula.