There is a hole in the buttocks has been bleeding, consider the possibility of anal fistula, at this time there can be bloody secretions from the external mouth of the fistula continuous or intermittent outflow, it is recommended to timely treatment, so as not to become complex anal fistula, and promote healing as early as possible. Most of the anal fistula is caused by perirectal anal canal abscess, abscess in the rupture or incision and drainage, can form a granulomatous channel around the anorectal canal, can be seen in the perianal skin, one or more external mouth, pus and blood secretion or pus can be discharged in the squeeze or a small amount of bloody secretion from the fistula continued to flow out of the external mouth. Fistula external opening often have pseudo-healing, abscess can be repeatedly ruptured, and ultimately the simple anal fistula into a complex anal fistula, the formation of multiple fistulas and external openings. Fistula is rarely self-healing, generally need surgical treatment, such as fistulotomy, hanging line therapy, anal fistula resection treatment of anal fistula.