The following reasons are common: 1, constipation, especially persistent constipation, longer age, prolonged defecation, abnormally dry stool, sheep feces-like, difficult to discharge, resulting in a serious sense of local blockage of the anus, common in the elderly and women, mostly due to the intestinal transport capacity, hormonal secretion abnormalities and other reasons. 2, export obstruction type, mostly seen in the rectal prolapse, rectal mucosal prolapse, etc. The disease is due to the special physiological structure of women, constipation, old age or after childbirth, the muscle of the posterior rectal wall of the vagina is relaxed, resulting in the protrusion of stool in the direction of the vagina instead of discharge from the anus, resulting in the inability to discharge stool smoothly, causing blockage of the anus, localized falling and a feeling of suffocation and distension. 3, anal sphincter damage, due to surgery or trauma and other reasons, resulting in damage to the anal sphincter. The muscle function is abnormal and cannot be contracted normally, causing local blockage due to the accumulation of stool.