Anal pus may be caused by the following conditions: first, it may be perianal abscess, mostly due to bacterial infection in the anal area and the emergence of local tissue suppurative reaction, mainly manifested in the anus around the emergence of touch thicker purulent mass, there will be more intense pain, and will become more painful with the aggravation of the condition, the serious may be difficult to sit or stand still, there is also a fever and symptoms such as an acute and severe pain in the abdomen. Secondly, it may be suffering from inflammatory external hemorrhoids, there will be pus-like changes in the hemorrhoidal nucleus area, swelling, itching, as well as painful sensations, especially if the recent hemorrhoidal condition is serious, the symptoms are more obvious, the pus bag will be bigger, and there will be a pushable sensation when pressed. In addition, it may be caused by inflammation of the hair follicle, local purulent infection, etc. It is best to go to the hospital for examination and differentiation of treatment.