The anus always flows outward, which can be seen in hemorrhoids, rectal prolapse or anal fistula and other conditions. 1. Hemorrhoids: if there are internal hemorrhoids in coughing, standing for a long time or weight-bearing frequent prolapse outside the anus, can cause anal edema as well as oozing increased, can cause perianal moisture. 2. Rectal prolapse: due to anatomical factors (such as pelvic floor fascia weakness, surgical trauma injury to the perirectal nerves or muscles and other factors), increased abdominal pressure (such as diarrhea, constipation, multiple deliveries, etc.) or frequent prolapse of the rectal polyps and other reasons can cause rectal prolapse, with the aggravation of the prolapse, can cause anal incontinence, there is mucus flowing out of the anus, which may make perianal itching. 3. anal fistula: for the formation of granulomatous channels around the rectum of the anal canal, such as the occurrence of inter-anal sphincter fistula, can be seen near the anal verge of the external mouth, the external mouth of the fistula has a continuous or intermittent bloody, purulent or mucus secretion, secretion can be stimulated by the perianal skin moist, itchy, eczema formation. There is always discharge from the anus, it is recommended to consult a doctor, clear diagnosis, follow the doctor’s instructions to actively treat the primary disease, and pay attention to keep the perianal local hygiene clean.