Usually noticed when a patient experiences pain and swelling during a bowel movement, an anal abscess is an infected, pus-filled cavity near the anus and rectum. The patient may also have chills and fever. An abscess forms when a gland on the inside of the anus gets clogged with bacteria or feces. An infection forms causing the abscess. Nothing can be done to avoid an abscess; seeking immediate treatment when one forms is the best course of action.
The abscess often located on the buttock tissues near the anus, may burst open and drain. If there is pus involved, this often requires an antibiotic. If a hard nodule has formed, this is considered a pus filled cavity, and will not go away (even with antibiotics) unless it is physically drained. Drainage can be performed as an office procedure with injectable anesthesia. Larger or more complicated cases may require drainage in the operating room.
Pain pills will likely be prescribed and can easily treat the expected mild to moderate pain. There is little down time for patients, and if properly healed, recurrence rates for abscesses are small, although new ones can still form.
In about 35-50% of abscess cases, a complication occurs, which if the formation of an anal fistula. An anal fistula is a tunnel that is formed from a previous abscess to the outside skin on the buttocks. The tunnel is formed when the anal abscess ruptures, or is drained. Although the outside opening may close, the inside opening remains. When bacteria of feces enters the inside opening, the abscess may reform. Persistent anal abscesses are usually due to fistulas. Symptoms of an anal fistula include pain, fever, swelling, skin irritation and/or drainage of pus from the area. Nothing can be done to avoid a fistula; seeking immediate treatment when an abscess occurs is the best course of action.
Surgery is needed to cure a fistula. The surgery is usually done as an outpatient under anesthesia. It needs to be performed about six weeks after drainage of the initial abscess when inflammation is sufficiently decreased.
Fistula surgery should be done by a surgeon experienced in colon and rectal cases, because injury to the sphincter muscles can occur as a surgical complication, and this can cause fecal incontinence. This surgery includes opening up the fistula tunnel with a substance that obliterates the tract.
The recovery for fistula surgery brings mild to moderate pain for the first week which can be controlled with pain pills. Down time for the patient is minimal.