In simple (or low) fistulas, a fistulotomy is performed. This is a straightforward operation. It is usually performed under general anaesthetic and as a day procedure. An examination is performed under anaesthetic to confirm the fistula and detail the anatomy. A probe is passed through it revealing both the external (perianal skin) opening and the internal (anal canal) opening. The fistula is laid open leaving an open wound in the perianal region that heals from the bottom up. The success of this procedure is over 95%.
What to expect post-operatively
The perianal wound will take some time to heal. Depending on the size, it can take between 2 and 6 weeks to completely heal.
Local anaesthetic will be injected into the wound at the end of the operation and therefore you should be comfortable when you wake up. There will be discomfort in the perianal region for the first few days to some weeks afterwards. You should take regular analgesia in the first 48 hours including paracetamol (Panadol) 1g (2 tabs) every 4-6 hours (max 8 tabs per day) and an anti-inflammatory such as ibuprofen (nurofen) 400mg every 4 – 6 hours. You may be given a prescription for a stronger pain killer such as oxycodone (endone) or tramal (tramadol) to use in addition as well. After 48 hours, use the painkillers only if needed.
Most commonly, no dressings are needed in the wound and a simple sanitary pad should be worn in the under wear to collect any discharge. Occasionally, daily internal dressings are needed and a district nurse will be organised to do this at home. Discharge from the wound is expected and can last for weeks. This is normal. The discharge can be blood stained and/or pus like. Keep the wound clean by showering with soap and water or by taking a salt bath (add table salt to a warm bath), pat the wound dry and replace the sanitary pad.
It is important to keep the bowel moving. Use either movicol 1-2 sachets daily or Metamucil 1-2 sachets daily if needed for a few weeks (especially if using endone). Try not to strain.
You can return to work and exercise when you feel comfortable. This may be a couple of days for some people and some weeks for others.
Complications are unusual.
Excessive bleeding – more than half a cupful that cannot be controlled by simple pressure on the wound
Infection – this is rare. A high fever, chills or spreading redness at the site may indicate infection
Recurrence of the fistula or perianal abscess
Faecal Incontinence – this is rare and if happens, is usually mild