Overview
An anal fistula is a small abnormal tunnel that forms between the inside of the back passage and the skin near the anus, usually after an abscess (a collection of pus) has drained or been drained. It causes ongoing discharge, discomfort and recurrent swelling near the anus. It does not heal on its own and is treated with surgery. It is a common condition in India, and early treatment prevents repeated painful abscesses.
Symptoms
- A small opening in the skin near the anus that discharges pus or fluid
- Recurrent painful swelling and abscesses near the anus
- Discomfort or pain, worse when sitting or passing stools
- Skin irritation around the anus
- Sometimes bleeding or a bad smell from the discharge
When to see a doctor
See a doctor for recurring anal swelling, pus discharge or an opening near the anus — a fistula needs surgical treatment to heal.
Causes
Usually an anal gland infection that forms an abscess and then a tunnel; also linked to conditions like Crohn's disease and tuberculosis.