An anal abscess is an infected cavity filled with pus that can be found in several locations around the anus and rectum. The symptoms of an anal abscess include pain around the anus, redness or swelling in the anal area, fatigue, and generally not feeling well. Sometimes an anal abscess will be accompanied by fever or chills. If an abscess builds up enough pressure, it may spontaneously drain, providing relief.
Most anal abscesses are thought to be due to an anal gland infection. This is known as the "cryptoglandular hypothesis." There are seven to eight small anal glands located in the anal crypts just inside of the anus. They produce mucus to aid in elimination. If one of these glands becomes impacted with fecal material it can cause an anal abscess. Because the glands are located up and down the anal crypts, the abscess can manifest in a variety of locations. Less common causes of anal abscesses include sexually transmitted diseases, hair follicle infections and sweat gland infections. People with a lowered immune system and inflammatory bowel disease are more prone to anal abscesses.
Most abscesses are small and located near the anal opening. Some abscesses are deeper and cannot be easily seen by visual examination. Gentle palpation may reveal the location of a deep abscess. Sometimes CT scans are used to evaluate the location and extent of an anal abscess. Some abscesses can become very large with cellulitis developing in the surrounding tissues, while other abscesses can develop complex horseshoe extensions involving both sides of the buttocks.
The treatment of an abscess is surgical drainage under most circumstances. An incision is made in the skin near the anus to drain the infection. This can be done in a doctor’s office with a local anesthetic or in an operating room under deeper anesthesia. Hospitalization may be required for patients prone to more significant infections such as diabetics or patients with decreased immunity.
Antibiotics alone are a poor alternative to drainage of the infection. For uncomplicated abscesses, the addition of antibiotics to surgical drainage does not improve healing time or reduce the potential for recurrences. There are some conditions in which antibiotics are indicated, such as for patients with compromised or altered immunity, some cardiac valvular conditions or extensive cellulitis. A comprehensive discussion of your past medical history and a physical exam are important to determine if antibiotics are indicated.
If antibiotics have been prescribed, a probiotic will aid in recovery of the normal intestinal bacteria and increase tolerability. Probiotics, such as Lactobacillus spp., Bifidobacterium spp. and Saccharomyces boulardii are living microorganisms that confer health benefits in the host. They are taken with food or as capsules/tablets and powder. Probiotics improve antibiotic therapy as they reduce microbial adhesion and growth by bacteriocins or other inhibitory compounds, possess immunomodulatory properties and improve intestinal barrier integrity. There are many probiotics on the market so be sure to read labels and choose one with a helpful bacterial strain or combination of the strains mentioned above. Also, many food products contain probiotics, such as yogurt, unpasteurized sauerkraut, miso soup, tempeh (fermented soy), acidophilus milk, sourdough bread, kefir, and gouda cheese.
The best thing to do after the drainage of an abscess is to take it easy and soak in warm water. This encourages the infected material to completely drain. This can be done for several days until the skin incision heals closed. If you are unable to sit in a tub, a gentle shower nozzle to the area of the abscess is useful as well.
Successful healing occurs in about 50% of people with a perirectal abscess. Some people will go on to develop an anal fistula. If an anal abscess does not heal completely in six to eight weeks, it could be the sign of an anal fistula
An anal fistula is an abnormal tunnel that connects an anal gland to the point of external drainage, whether it spontaneously drained or was surgically drained. This tunnel does not hurt if the external opening freely drains, but does cause notable seepage. If the external opening heals closed, then pressure will build up in the tract, with accompanying pain, until it ruptures, bringing relief. These pain-drainage type of symptoms can continue in six to eight week cycles. This is the sign of an anal fistula. Anal fistulas usually require surgical repair for complete healing.