Diseases that cause pus to flow from the anus include perianal abscesses anal fistulas as well as boils. The pus is sometimes green, but mostly yellow. When a boil or wound is pus-filled, the pus mostly has a special smell. So what is the difference between a perianal abscess and an anal fistula? Difference between perianal abscess and anal fistula Perianal abscess: Acute purulent infection occurs in the soft tissue around the anal canal and rectum or in the interstices around them, and an abscess is formed, called perianal and rectal abscess. It is characterized by self-rupture or often forms an anal fistula after surgical incision and drainage. It is a common anorectal disease and the acute phase of the pathological process of inflammation of the anal canal and rectum, and anal fistula is the chronic phase. Anal fistula: Anal fistula is a sinus tract formed around the anus, where small holes in the skin around the anus repeatedly flow pus and are generally painless. Anal fistula: Most of them are the sequelae of perianal abscesses, which are not actively treated because they are not painful and often cause pain due to the recurrence of the first grass hemorrhoids common symptoms of perianal abscesses. In addition, the skin around the anus is inflamed because of the flow of pus, and the skin around the anus must be kept clean frequently, otherwise it will not be possible to treat the anal fistula. The difference between perianal abscess and anal fistula is also shown by the fact that other hemorrhoids can hopefully be cured by life therapy, or at least most of them can get better through life therapy, but unfortunately, only anal fistula cannot be cured by life therapy, and surgery is the only radical cure. Therefore, it is important to undergo surgery as soon as possible. In addition, it is relatively easy to distinguish anal fistula from powdery infection and sepsis. However, it is difficult for a layman to distinguish between the three, including boils, and it is best to have them treated by a doctor. Treatment of perianal abscesses and fistulas A few perianal abscesses can be dissipated with antibiotics, hot water sitz baths and local physical therapy, but most require surgery, which can be done in two ways. As most perianal abscesses require surgical incision and drainage, some contraindications to the treatment of perianal abscesses should be noted.