The anal fistula results from an abnormal passage that develops as a result of a para-anal abscess. The abscess attempts to create a path to drain outwardly.
Depending on the position of the path and how it passes through the sphincter it is classed as Fistula:
inter-, trans-, supra- or extra-sphincter.
Fistula treatment is complex and must be adapted to the passages that are not always pre-operatively identified despite conventional radiological examinations.
Your surgeon will excise the fistula,
open its path (flattening)
excise and do a mucosal flap to obliterate the internal orifice or
excise and rebuild the anal canal
Dr Xavier Delgadillo