Ano-rectal fistula

Commonly referred to as a Fistula-in-ano, it is a relatively common condition usually occurring between the ages of 30-60 years. Males tend to be more susceptible than females.

What is an ano-rectal fistula?

An ano-rectal fistula is an abnormal communication or tract between the rectum and perineum with an opening at each end. Faeces enter the track from the anus and provoke chronic infection, which prevents the fistula from healing. The faeces and inflammatory fluid discharge from the other end of the track on the skin beside the anus.

What are the symptoms?

Symptoms can include:

  • Skin irritation around the anus
  • Pain with bowel movements
  • Smelly discharge from near your anus
  • Recurrent anal abscesses
  • Pain and swelling near the anus

What causes an ano-rectal fistula?

The most common cause of ano-rectal fistula is an abscess from an infected anal gland which presents as a painful red swollen lump, like a boil next to the anus which may spread into the buttock.

Perineal injuries such as those received during a fall, from a road traffic injury or from a tear during childbirth may also result in the formation of an ano-rectal fistula.

How is ano-rectal fistula diagnosed?

Ano-rectal fistula are usually diagnosed by assessing your bowel habits and any abdominal discomfort you have been feeling. An examination of the area around your anus will be required to look for any evidence of swelling, irritation or signs of infection.

What are the treatments?

Surgery is usually necessary to treat an ano-rectal fistula

  • Insertion of a Seton for drainage. A Seton is a narrow silicone band which is passed through the fistulous track and tied outside the anus. The Seton then acts as a drain to allow pus to escape and therefore help settle infection. When successful this method may avoid the need for surgical intervention, but often a further procedure is required to heal the fistula after infection has settled.
  • Laying open of the fistulous track. The track is excised and the lining is scraped away leaving new healthy tissue to promote the healing process.
  • Rectal endo-muscal flap closure. The fistula is excised and a flap of healthy rectal mucosa is stitched over the internal opening to close it off. This method occasionally requires the formation of a temporary colostomy to rest the bowel while healing takes place.
  • LIFT procedure. Ligation (tying off) of the fistulous track between the sphincter muscles.
  • Collagen plug. Plugging the track with collagen to seal the track.