Which one is more serious, colitis or proctitis, should be further judged according to the scope of involvement of lesions and clinical symptoms. 1. Scope of involvement: if the lesion has been involved in the ascending colon, transverse colon, rectum and other parts, and has occurred in the submucosal layer of the involvement, colitis is more serious, if the lesion is only limited to the rectum, the inflammation is relatively light. 2. Clinical symptoms: colitis, if there is mucous pus and blood stools, mucous membrane with bloody secretion, ulcerative lesions, contact bleeding phenomenon, the symptoms of colitis is more serious, and vice versa for the proctitis is more serious. Both diseases are inflammatory lesions, can not be based on the name of the disease and determine which disease is more serious, to be judged on a case-by-case basis.