What is it?
A pilonidal sinus is an infected tract under the skin between the buttocks. A pilonidal sinus is usually a nest of hair under the skin over the tailbone. These hairs pass inwards through the little holes (sinuses) in the skin. Germs build up among the hairs, causing pain, swelling and discharge. Sometimes such sinuses form near old scars or between the fingers.

The Surgery
The aim is to get rid of the hairs and close off the space under the skin. The problems are to get good healing and to stop the pilonidal sinus coming back. There are several surgeries for this, ranging from very small to major plastic surgery operations. In all the procedures tissue is taken out. The differences are in the ways of getting the space healed up properly. One way is to let nature fill in the space with scar tissue. Another is to stitch up the space and let the wound heal. You would usually have a general anesthetic and be completely unconscious. For a small operation, numbing the skin with a local anesthetic injection may be all that is needed. The skin with the sinuses is cut out. The space with its hairs is either cleaned out or is cut out. The space may be left open to fill in from inside to leave a wildish scar. Alternatively the space is stitched up to heal with a narrow scar. Bigger operations are designed to move the scars away from the midline. Ask your surgeon which way he finds best. Most operations mean a day or two in hospital. The small operations with local anesthesia are usually as day’s hospitalization.

Any Alternatives
If you leave things as they are, the trouble will remain. It may get better on its own by the time you are 40 years old or so. Burning the deeper tissue with a phenol treatment is an alternative. It does not necessarily lead to better healing than the small operation.

Before the operation
Stop smoking and try to reduce weight if you are overweight. (See Healthy Living). If you know that you have problems with your blood pressure, heart, or lungs, consult your family doctor and check whether these are under control. Even consult the hospital about taking the Pill or hormone replacement therapy (HRT). Check you have a relative or friend who can come with you to the hospital, take you home, and look after you for the first week after the surgery. Sort out any tablets, medicines, inhalers that you are using. Please retain them in their original boxes and packets. Always carry them to the hospital. On the ward, you may be checked for past illnesses and may have special tests to make sure that you are well prepared and that you can have the operation as safely as possible. Please tell the doctors and nurses of any allergies to tablets, medicines or dressings. You will have the surgery explained to you and will be asked to fill in an operation consent form. Many hospitals now run special preadmission clinics, where you visit for an hour or two, a few weeks or so before the operation for these tests.

After - In Hospital
If you have had only a local anesthetic you will be completely conscious and alert throughout. Local anesthetic will wear off after an hour or two, so the wound gradually gets uncomfortable. Take painkillers early to control any pain. Feeling in the wound may come back quicker after a general anesthetic so that you should be ready to take painkillers inside an hour. The wound should be just about pain-free within a day or so. A general anesthetic will make you slow, clumsy and forgetful for about 24 hours. Do not make important decisions, drive a car, use machinery, or even boil a kettle during that time. The wound will have a dressing. This may be held on by elastic net pants. Sometimes the space in the wound is packed with an oily dressing or a special silicone sponge. Usually the nurses on the ward and the district nurses arrange to change the dressings as needed and to take out the stitches. Sometimes the wound is examined and cleaned in the out-patient department. The arrangements will be explained to you. The nurses will advise about sick notes, certificates etc.

After - At Home
The advice below applies to a patient who has had a small operation under local anesthesia. You should lie on the dressings for one hour or so before going home. If there is any bleeding, add extra dressings and lie on them. If the bleeding continues at home, come back to the ward. You will be given a supply of dressings and an Out Patient appointment. The next day: Soak in a bath of warm water without salt for 30 minutes, and pull out all the dressings. Place a new dressing over the wound, held in place by underpants. Each day: Remove the dressing, have a bath and apply a new dressing. There may be a bloody discharge for a day or two, but the discharge will then become yellow. To prevent the condition coming back, you should attend the Out Patient clinic or your surgery each week until the wound is healed completely. You can wash the wound area as soon as the dressing has been removed. Soap and warm tap water are entirely adequate. Salted water is not necessary. You can shower or bathe as often as you want. After a local anesthetic you can drive straight away. After a general anesthetic you should wait 24 hours before driving. You should be able to go back to work within 24 hours after the minor operation without stitches. A larger operation with stitches usually means two weeks off a light job and perhaps four weeks off a heavy job. Avoid sport until the wound has fully healed. This will be after three or four weeks after stitching, and six or seven weeks if the space has to fill in with scar tissue.