Editing Anal fistula surgery (section)

=== Exploration for fistula: ===

** Palpate with finger in anal      canal and thumb on peri-anal skin (can sometimes feel the internal      opening as an uneven area at the dentate line)
** Insert an anal retractor and      expose the suspect area
** Inject hydrogen peroxide      (can also use blue dye or milk) while watching the primary opening
** Insert a thin probe in the      direction indicated by Goodsall's rule
*** Assist by placing a clamp       near the external opening and pulling away from the anus
** If unable to define tract, terminate operation and get an MRI in      4-6 weeks, although can also do it straight away if necessary