Medical article
An anal fistula does not heal on its own
An anal fistula is an abnormal channel that forms between the inside of the anal canal and the skin around the anus. In most cases it results from an earlier perianal abscess (paraproctitis), that is, an abscess filled with pus. The main problem with a fistula is that it comes back: the opening closes, pus collects, it opens again, and this cycle can go on for years.
Why does a fistula not heal on its own?
Over time, the walls of the fistula channel become lined with epithelium, and the channel turns into a permanent structure. Antibiotics reduce the inflammation temporarily but do not eliminate the channel. For this reason, the permanent treatment of a fistula is surgical.
Symptoms
- A small opening in the skin around the anus
- Periodic discharge of pus or blood, soiling of clothing
- Recurring swelling and pain
- Itching and skin irritation
The role of MRI in diagnosis
The course of a fistula can be simple or complex: the channel may pass through part of the sphincter muscles and may branch. MRI shows how the fistula relates to the sphincter and thereby clarifies the surgical plan. This is especially important in complex and recurrent fistulas.
Treatment
The methods used are opening or removing the fistula channel (fistulotomy, fistulectomy), placing a seton for staged treatment, and sphincter-preserving techniques. The choice depends on the type of fistula.
The goal
The goal is not only to eliminate the fistula but also to preserve bowel control and reduce the risk of recurrence. A fistula whose treatment is delayed may branch over time and become harder to treat. Seeing a doctor early means a simpler operation.