Anal fistula surgery recovery timeline: what to expect and when

The NHS explains that surgery is often needed for anal fistulas because they do not usually heal by themselves, that it is usually carried out under general anaesthetic, and that in many cases it is not necessary to stay in hospital overnight. Recovery then has two overlapping parts: getting over the operation itself, which usually takes days, and the healing of the wound or the fistula, which can take weeks or months.

How long that second part takes depends largely on the operation. A fistulotomy cuts open the whole length of the fistula so that it heals as a flat scar. A seton, by contrast, is a piece of surgical thread left in the fistula, which the NHS says is left in place for several weeks to keep it open and allow it to drain, and which may be followed by further procedures.

Guy's and St Thomas' says you should expect some discomfort after surgery and that the area can be quite painful for the first couple of days, sometimes seeming to get worse before it becomes more comfortable. It advises taking prescribed painkillers regularly, which helps keep you comfortable, and notes that you might not need them if the area is pain-free.

You may be given laxatives to keep stools soft. The trust says you might have discomfort and a little bleeding when you first open your bowels, that you should go when you feel the urge, and that taking painkillers 15 to 20 minutes beforehand can help. The Bradford leaflet similarly advises more fibre and fluids to avoid constipation and straining that could dislodge a seton, and says you should contact the team if constipation lasts more than three days despite laxatives.

If you are given antibiotics called metronidazole, Guy's and St Thomas' advises not drinking alcohol while taking them and until 2 days after finishing the course, because the combination can cause unpleasant reactions such as sickness, flushing and palpitations.

The practical advice is consistent across NHS sources. Keep the area clean and gently bathe the wound in a warm bath each day if possible, which also helps with pain. Guy's and St Thomas' advises not using soap, salt or perfumed products in the water until the wound has healed, and to wash or use alcohol-free wipes after a bowel movement.

It says your surgeon may ask you to digitate your wound, moving a finger along it to prevent the top layer of skin healing too quickly, which can help stop the fistula coming back. If you cannot do this yourself, the practice nurse at your GP surgery can be asked. Where a fistulotomy has been done, the Northern Care Alliance leaflet says often the wound just needs to be kept clean, with a small pad to prevent soiling and occasionally a small dressing.

If a seton has been placed, Guy's and St Thomas' says mucus may leak from the wound, which is common, and that a pad and more frequent bathing may help. The Bradford leaflet says the fistula may continue to drain as before for several weeks or months after a seton is inserted. The Northern Care Alliance leaflet describes daily flossing of the seton to prevent blockage, which the nursing team can demonstrate.

Sources differ in detail, so follow the advice from your own surgical team. The common thread is gradual return to normal.

• Work: most people take a few days off work (Guy's and St Thomas'), depending on how they feel and whether the job is active.

• Exercise and lifting: avoid heavy activity such as lifting, exercise or running during the first week or so (Guy's and St Thomas'), or for up to two weeks (Bradford).

• Swimming: not until the wound has healed (Guy's and St Thomas').

• Sex: as soon as you feel comfortable (Guy's and St Thomas'), whereas the Bradford leaflet advises abstaining for up to two weeks after seton surgery because of the risk of dislodging the suture.

• Follow-up: Guy's and St Thomas' says no routine follow-up is required unless the surgeon specifies it, and that you can start a follow-up yourself if there are concerns within the first 6 months.

The Bradford leaflet says that after laying open a fistula the wound will eventually heal but can take several weeks or months. For setons, the Northern Care Alliance leaflet says they can remain for weeks, months or years, that the length of time is often not known in advance, and that more than one seton may be needed. Bradford says fistula surgery is often done in stages, with further surgery taking place within weeks or months of the first procedure.

The NHS describes other procedures, including advancement flap, LIFT, endoscopic ablation, laser, fibrin glue and bioprosthetic plug, each with different success rates and recovery. It also lists the main risks of fistula surgery as infection, recurrence and bowel incontinence, although it says severe incontinence is rare. The Northern Care Alliance leaflet notes that after a fistulotomy you may initially notice reduced ability to control wind, which should resolve with time.

Guy's and St Thomas' advises speaking to the ward or department if you keep getting bleeding from the wound, and asking for an urgent GP appointment or going to A&E if you feel generally unwell or have a high temperature. The Bradford leaflet lists excessive pain not relieved by over-the-counter painkillers, continuous bleeding, the seton falling out, constipation for more than three days, and signs of infection such as a temperature over 38 degrees C or vomiting.

The Northern Care Alliance leaflet adds night sweats, pressure building in the bottom like sitting on a ball, redness or heat at the site of the fistula, a change in discharge and increasing pain. Out of hours, it advises contacting NHS 111 or attending A&E.