A fistula is a tiny channel or tract that develops in the presence of inflammation and infection. It may or may not be associated with an abscess. The channel usually runs from the rectum to an opening in the skin around the anus.
A throbbing, constant pain
Irritation of skin around the anus
Evidence of pus or blood when passing stools
Cancer of the rectum, etc.
Fistulectomy excision of whole of the fistulous tract from external opening to internal opening. It is laid open or sutured primarily.