A 40 years old male patient presented to surgery OPD with history of serous discharge from an external opening located in perianal region(posterior openings). On examination, the location of external opening was at 4'O clock position. What is the location of internal opening?
High-Yield Explanation
Goodsall's Rule: Anterior openings - Straight tracks - Location of external & internal openings are in the same position. Eg: Location of external opening is 1'0 clock position the location of internal opening is also at 1'0 clock position Posterior openings - Curved tracks - Location of external & internal opening - Not same - Eg: External opening - 4,5,6,7,8,'O clockInternal opening - 6'O clock position Exceptions 1. Multiple external openings: - Posterior rule is applied - Internal opening - posteriorly in midline 2. Location of external opening > 3cms from anal verge: - Posterior rule will be applied