Anal Fistula:
An anal fistula is a tunnel between the anal canal and skin, often caused by an untreated abscess. It can also result from Crohn’s disease, diverticulitis, or infections like TB or HIV.
Causes:
- Primary Cause: Poorly healed anal abscess (25-50% of cases).
- Other Causes: Crohn’s disease, diverticulitis, TB, or HIV.