Anal Abscess & Fistula
What is an anal abscess / fistula?
An anal abscess is a painful, infected cavity filled with pus and located near the anus or rectum. If the abscess is large, a person may develop fever, chills or a general ill feeling. An anal fistula is a small tunnel which starts inside the anus and usually exits at one or more places on the skin of the buttocks outside the anus. A fistula may cause irritation to the skin around the anus, itching or drainage of stool or mucus.
What causes an abscess?
An abscess is caused by an infection of a small gland just inside the anus. Bacteria or foreign matter enters the tissue through the gland. Certain conditions, such as colitis or other inflammations of the intestine, may make these infections more likely.
How is an abscess treated?
In order for an abscess to heal, the pus must be removed from the cavity. Sometimes, the abscess may drain spontaneously and the patient may feel a sudden relief from pain. More often however, the surgeon must make an incision through the skin near the anus to relieve pressure and allow the pus to drain. If the abscess is small and near the surface of the skin, this usually can be accomplished in the doctor’s office using a local anesthetic. A very large or deep abscess may require a more extensive operation. In these circumstances, the drainage procedure is often performed in the hospital or outpatient surgical setting. Antibiotics are not an alternative to draining the pus.
How long will it take before I feel better?
When the pus is allowed to drain, relief is rapid and dramatic. The abscess may continue to drain for several weeks until all the infection is gone, and the cavity which contained the pus has a chance to completely heal.
What should be done at home while the abscess is healing?
Soaking the affected area in warm water (a sitz bath) for 20 minutes, three or four times a day, will help to ease the pain and speed healing. This should be done for as long as the area is uncomfortable. Drainage may continue for several weeks, and is a healthy sign of healing. It may be necessary to wear a light gauze dressing or mini-pad inside the underwear to keep the drainage from soiling clothing. Bowel movements will no affect the healing process.
Does an abscess always become a fistula?
About half of the people who get an abscess will ultimately develop a fistula. There is usually no way to predict who will and who will not develop a fistula.
How long will it take to determine if I have developed a fistula?
Usually this is evident within 4 to 6 weeks after the abscess is drained, though fistulas occasionally may develop months or years later. Sometimes a fistula is discovered only after the development of another abscess in the same area.
How is a fistula treated?
Fistulas require a surgical procedure for treatment. This operation almost always can be preformed in an Outpatient Surgery department without an overnight hospital stay. The discomfort after such a procedure is mild to moderate and often is easily controlled by pain medication for a few days. The amount of time lost from work typically is minimal. This operation usually does not interfere with one’s ability to control bowel movements.