Anal fistula

Most anal fistulas are caused by an abscess (a collection of pus) that has developed in your anal canal. The pus can drain away onto the skin on its own or by an operation. A fistula happens when the track, made by the pus on the way to the surface of the skin, stays open.

Most anal fistulas do not heal on their own. Surgery is usually needed to treat the problem.

What does the operation involve?

Surgery for anal fistula is usually performed under a general anaesthetic. The operation usually takes about half an hour.

The type of surgery you need will depend on where the fistula is. If the fistula is below or crosses the lower part of the sphincter muscles, your surgeon will cut the fistula open to the skin and leave the wound open so that it can heal with healthy tissue.

If the fistula has branches that pass through the upper part of the sphincter muscles, your surgeon may place a special stitch (called a seton stitch) in the fistula to allow pus to drain easily.

The fistula may be suitable for treatment with a plug made from tissue. Your surgeon will not need to make a cut in the sphincter muscle.

If the fistula reaches above your sphincter muscles, you may need to have a temporary colostomy (bowel opening onto the skin). However, this is not common.

After your operation

Your length of stay in hospital will depend on the extent of your surgery. Be sure and discuss this with your surgeon. You may need medication to relieve any pain.

You will need to wear a dressing over your surgical wound until it has healed. You will need to visit your GP or return to the hospital to have your dressing changed and check how the wound is healing. It can take up to six weeks for your wound to heal.

You may experience some bleeding or discharge in the first few weeks. Wearing a pad will protect your underclothing from staining.

You may be prescribed antibiotics and laxatives. Be sure and follow the instructions on taking these medications.

You will need to rest for the first few days after your operation. You should avoid sitting for long periods. So that your wound can heal properly you should avoid too much walking.

Be sure and discuss any return to work with your surgeon.

Most people make a good recovery and return to normal activities following anal fistula repair. As with any surgery there can be complications:

• Infection
• Bleeding
• Pain
  

Specific complications of anal fistula repair:

• Difficulty passing urine
• Involuntarily passing wind or loose faeces
• Bowel incontinence