Anal Fistula
Based on the location of anal fistula, it is classified on shown in the image.
Anal Fistula
Fissures become wounds and at the same time the rectum is blocked by the hemorrhoids, the stool cannot pass out easily and also leaving small holes between the rectum and anus. In other words, it is a granulated track communicating between perianal skin to anal canal or rectum. Pus & blood discharge occurs in it.
Types
Depending on their relationship with the internal and external sphincter muscles, fistulae are classified into five types:
EXTRASPHINCTERIC FISTULAE
It is begin at the rectum or sigmoid colon and proceed downward, through the levator ani muscle and open into the skin surrounding the anus. Note that this type does not arise from the dentate line (where the anal glands are located). Causes of this type could be from a rectal, pelvic or supralevator origin, usually secondary to Crohn's disease or an inflammatory process such as appendiceal or diverticular abscesses.
SUPRASPHINCTERIC FISTULAE
It is begin between the internal and external sphincter muscles, extend above and cross the puborectalis muscle, proceed downward between the puborectalis and levator ani muscles, and open an inch or more away from the anus.
TRANSPHINCTERIC FISTULAE
It is begin between the internal and external sphincter muscles or behind the anus, cross the external sphincter muscle and open an inch or more away from the anus. These may take a 'U' shape and form multiple external openings. This is sometimes termed a 'horseshoe fistula.
INTERSPHINCTERIC FISTULAE
It is begin between the internal and external sphincter muscles, pass through the internal sphincter muscle, and open very close to the anus.
SUBMUCOSAL FISTULAE
It is pass superficially beneath the submucosa and do not cross either sphincter muscle.