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Anal Fistulotomy

Pre-operative Preparation for a Anal Fistulotomy procedure

There is some important information about the pre-operative preparation for this procedure. It is imperative that you read this.

Read about Anorectal Pre-operative Preparation


A fistulotomy is the standard technique of managing an anal fistula. The latter usually arises as a consequence of a previous perianal abscess that has either drained spontaneously or has required formal incision and drainage. It is performed on any fistula that does not involve a significant amount of the anal sphincter complex, thereby reducing the risk of incontinence effectively to zero. The decision to perform a fistulotomy, as opposed to placement of a seton drain (see below), will almost certainly have been made by Dr Renaut prior to the surgery. However the final decision can sometimes only be made with the patient asleep under general anaesthesia and following probing of the fistula tract to determine the position of the latter in relation to the sphincter complex. If it is deemed safe to proceed with a fistulotomy then Dr Renaut will do so. If not he will place a seton drain. He very much airs on the side of safety and as a result has never had a patient complain of incontinence post operatively.

The operation is performed under general anaesthesia usually as a day case.

The intention of performing a fistulotomy is to open up the fistula tract and allow it to heal from the base upwards by what’s called secondary intention. Effectively there is an open wound running through the edge of the anus from the outside opening of the fistula to the inside opening. Depending on the depth of the wound it may require a daily dressing to be placed within the wound. This is done by the GP practice nurse. The ideal timing is after the patient has opened their bowels first thing in the morning, and following a thorough irrigation in the shower with soap and water. The dressing then sits in the wound for the rest of the day and is designed to keep the wound open and allow it to heal from the base up without closing over prematurely and reforming another fistula.

If the dressing falls out prematurely during the day (such as with another bowel motion) it is not important that it is not redressed until the following day. If a single days dressing is missed similarly this is not important.

Despite the fact that there is an open wound through which faeces are passing close by, the incidence of infection is exceedingly rare. The important aspect in helping to prevent this is keeping the wound thoroughly cleansed with daily soap and water in the shower.

In approximately ten days the wound is no longer deep enough to accept the dressing and it is therefore left for it to heal without further intervention, apart from once again regular cleaning with soap and water.

Post-operative Care following a Anal Fistulotomy procedure

Following your procedure there are a number of things of which you need to be aware.


It is inevitable that you will experience some discomfort following your surgery in the region of where the fistulotomy has been performed. As it is a relatively small incision this discomfort should be no greater than the pain you were experiencing from the fistula. Long acting local anaesthetic will have been injected into the wounds but after a few hours this effect will wear off. Before it does so it is important to have some pain killers on board and to continue these on a regular basis. You will be sent home with some pain killers - my preference is either Panadeine Forte or Nurofen. I recommend that you take these initially on a regular basis as directed on the packet. After about 48hrs it should be necessary to take these only as required.

Bowel activity

It is important to maintain normal bowel activity after the surgery, but you would not normally expect a bowel motion for the first 2-3 days after your operation. Opening your bowels will increase the level of discomfort initially and it is important to keep yourself regular with an intake of adequate fibre. You should also drink plenty of water. If you feel that you are getting constipated then a fibre supplement such as Metamucil, Mucilax or Normocol should suffice.


It is not unusual to experience some minor spotting of blood and discharge of clear mucus. If this is excessive then simply wear a small pad.


You may experience swelling in the perianal region lasting for a few days but this will subsided of its own accord in due course.

Physical Activity (including sexual activity)

Resuming physical activity is largely one of common sense. Certainly moving around the house and going for short walks in the first couple of days is desirable. Anything more than this will be destined to cause more discomfort. An increase in the level of activity should be guided by the level of discomfort. You should be able to resume your normal day to day activities within a few days, so long as this does not include marked exertion. You should however be able to return to the gym or similar activities within a couple of weeks.

Follow up

Dr Renaut will see you for a review in his office approximately four to six weeks after the surgery. He routinely notifies your GP of all procedures and your progress.

A seton drain is placed in the event that it is unsafe to proceed with a fistulotomy. This can usually be determined preoperatively but maybe determined at the time of operation following probing of the fistula tract and determination of the relationship of the fistula tract to the sphincter complex.

A fistulotomy will be performed in preference to the placement of a seton drain if it is deemed safe to do so, simply because healing of a fistulotomy wound is a much quicker process than dealing with it by a seton drain.

The principle of the seton drain is to establish and allow free drainage through the fistula tract via the drain. The drain consists of small silastic tube (very much like a rubber band) that is passed through the tract and bought out through the anus and then tied loosely to the end that is coming out of the external opening. As far as what the patient experiences, it is very much like having a rubber band hanging out of the anus and after about forty eight hours the patient no longer notices its presence. Once the seton is in place normal bowel and cleaning activities are performed exactly as usual.

At the time of the placement of the seton drain Dr Renaut may perform a partial fistulotomy of the fistula tract that involves just the subcutaneous tissues around the anus but not the muscle itself.

Approximately two weeks after the placement of the seton drain Dr Renaut will see the patient in his office and the tightening process will start. At weekly intervals the drain will be tightened a little bit more and as it is tightened it cuts through very slowly with pressure, all the time maintaining the integrity of the sphincter complex by allowing it to heal up behind with scar tissue. Eventually it will cut all the way through and at some stage it will simply fall out, usually in the shower. At that point there is an effect a very shallow fistulotomy wound left which will then heal of its own accord.

Related Information

Read about Anal Fistula