An anal fistula is not life-threatening, but it does not resolve on its own and will not improve without treatment. Left untreated, a fistula causes chronic discharge that is socially inconvenient and uncomfortable. It can also lead to recurrent perianal abscesses — each episode requiring drainage and antibiotics. A long-standing untreated fistula can develop complex branching tracts that make eventual surgery more difficult, and there is a very rare association between very long-standing fistulas and malignant change. The practical advice: do not ignore a fistula, but do not panic about it either. It needs surgery, and the sooner it is properly treated, the simpler the surgery tends to be.

In the vast majority of cases, no. Unlike fissures, which can heal with conservative care, fistulas are epithelialised tracts — the lining of the tunnel prevents spontaneous closure. Antibiotics can temporarily reduce symptoms but do not eliminate the tract. The standard of care is surgical treatment, and the evidence supports it. Timing matters: if there is active infection (an abscess), we drain the abscess first and let the inflammation settle before the definitive fistula surgery. The question is not whether to operate, but which technique gives the highest cure rate with the least impact on sphincter function.

This is patients' biggest concern — and an understandable one. Protecting the anal sphincter muscles is the first priority in any fistula surgery. A simple fistula (crossing only a small part of the muscle) can be laid open (fistulotomy) safely. For a complex fistula, sphincter-preserving techniques such as LIFT or a seton are used instead. An experienced surgeon balances curing the fistula against preserving muscle function — the plan is chosen from the anatomy, not from a catalogue.

Recurrent fistula is a frustrating problem, and patients who experience it often feel that something was missed. They are usually right. The three most common reasons are: first, the internal opening was not identified or adequately addressed during surgery — the most common cause, and it underscores the importance of meticulous technique. Second, a secondary tract or branch was missed — complex fistulas can have multiple tracks, and pre-operative MRI helps identify them. Third, undiagnosed Crohn's disease — Crohn's causes fistulas that are inherently difficult to heal because the inflammatory condition impairs wound healing. This is precisely why colonoscopy is performed before fistula surgery in appropriate patients.

If your fistula has come back, read the guide to recurrent fistula & pilonidal surgery →

A perianal abscess requires prompt drainage. Do not wait for it to "burst on its own" or try to treat it with antibiotics alone — the pus needs to be drained surgically. The procedure is straightforward, often under local anaesthesia, and provides immediate pain relief. After drainage you will need wound care and follow-up. A reported 30-50% of patients who have an abscess will later develop a fistula — this may appear weeks to months after drainage. If you notice persistent discharge from the wound site after the abscess has healed, or a new external opening near the anus, this likely indicates a fistula and warrants evaluation. Get in touch for urgent evaluation if you suspect a perianal abscess.

It depends on the technique. A simple fistula (fistulotomy) — most patients return to work within 3-5 days, with full healing over 4-6 weeks. A complex fistula (seton or LIFT) can take longer — 6-8 weeks. During this period: warm sitz baths, fibre, analgesics, and regular clinic follow-up. Learn more about recovery after surgery.