| What is an anal fistula?
An anal fistula is an abnormal connection between the anus
and the skin. On the surface of the skin around the anus,
one or more 'holes' might be evident: these are the external
openings of thin passages that tunnel down towards the anal
canal.
What causes an anal fistula?
An anal fistula is usually the result of a previous abscess
in the area, which has been drained (of pus) but does not
fully heal. This results in persistent or intermittent discharge
of pus, blood or mucus. Usually, there is not much pain, although
an abscess can sometimes recur.
What is the surgery for an anal fistula?
Because very few fistulas heal on their own, surgery is needed
for almost all patients who have this condition.
What does the operation involve?
Surgery to treat a fistula can be simple or complex (according
to the nature of the fistula). Sometimes it is not possible
to tell before surgery what is the full extent of the fistula,
and so decisions are made while you are anaesthetised. Simple
fistulas can be ˜laid open' by cutting a small amount
of the anal skin and muscle to open up the tract. Fistulas
that are situated more deeply (complex fistulas) cannot be
treated like this because it would involve cutting too much
muscle and could result in incontinence. In these circumstances,
a variety of other treatments are available - and your surgeon
will discuss the options with you individually. Complex fistulas
are difficult to treat, and the surgery might be planned in
several stages over a period of weeks, months or even years.
What can go wrong after the operation?
Surgery to treat anal fistulas is generally a very safe operation
and carries few risks, but (as with any surgical procedure)
complications can occur. Since fistulas are closely linked
to the muscles that control the passage of faeces and gas,
surgeons are very careful in the decision-making process concerning
the nature of the surgery performed because there is a small
risk of damage to these muscles. For the majority of patients,
the laying open of the fistula does not involve a significant
portion of the anal muscles being cut, and the loss of continence
is not a risk. Nevertheless, any disturbance of the anal sphincter
muscles can lead to some degree of change in the ability to
control wind, liquid and, very occasionally, solid faeces
from the back passage.
Is there any special preparation before
the operation?
The details of any operation will be explained to you beforehand.
In general, before your admission for surgery, you should
be on a high-fibre diet and have a fluid intake of at least
6-10 glasses of water daily; this is to keep your bowel motion
soft. Just before your surgery, the nurse may give you an
enema to empty the bowel (depending on the type of surgery
you will have).
If you are overweight please try to reduce. This will reduce
the anaesthetic risk and optimise your recovery.
What kind of anaesthetic will I have
for this operation?
Several different kinds of anaesthesia can be used, and the
method will be tailored to your particular needs and wishes.
Most patients will require general anaesthesia, and will be
asleep for the entire procedure. Some patients are better
suited to a spinal or caudal anaesthetic. This is a small
injection in the lower back to numb the area so that you will
not feel the surgery. With a spinal or caudal anaesthetic,
you will be conscious and able to talk to the anaesthetist
during the procedure.
What kind of pain relief will be used
for the operation?
In order to minimise the pain associated with your operation,
a number of measures will be taken:
1. At the time of surgery, a local anaesthetic will be injected.
This will provide pain relief for much of the day.
2. After surgery, you will be given painkillers to take
by mouth.
3. You should have baths (a 15-minute bath in water as warm
as you can tolerate) several times daily, or as often as you
require them. These are very soothing and can provide several
hours of pain relief.
What should I look out for after the
operation?
After your operation, you should contact your Doctor if you
notice any of the following problems:
1. Increasing pain, redness, swelling or discharge
2. Severe bleeding
3. Constipation for more than three days, despite using a
laxative
4. Difficulty in passing urine
5. High temperature (over 38ºC) or chills
6. Nausea or vomiting
How fast will I recover after the operation?
Within one to two hours of your operation, you will be encouraged
to get up and walk around. You may eat and drink normally,
and (as before) we recommend a high-fibre diet and a fluid
intake of at least 10 glasses of water daily. For a planned
day-case surgery, you will be discharged from hospital on
the same day, or the following day. You should expect to pass
faeces within one to three days, and this might be uncomfortable
at first; a small amount of bleeding or discharge is also
possible. Over the first few weeks, you might notice some
change in your ability to control wind, which should resolve
with time. Provided you feel comfortable, there are no restrictions
on activity and you may lift things, drive and go back to
work.
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