A 32-year-old man has a fistula-in-ano whose external opening lies in the right anterior perineum, close to the anal verge within 3 cm of it. According to Goodsall's rule, the expected course of the tract is:

• A A curved tract to the anterior midline crypt
• B A curved tract to the posterior midline crypt
• C A direct radial tract to the nearest anal crypt ✓
• D A blind tract ending in the ischiorectal fossa

Explanation

Goodsall's rule states that an external opening in the posterior half of the anus leads by a curved tract to the posterior midline crypt, whereas an anterior opening drains by a direct radial tract to the nearest crypt. The one exception is a very anterior external opening more than 3 cm from the verge, which also curves to the posterior midline. This patient's anterior opening lies close to the verge, so the direct radial course applies.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.