An anal abscess is an infected cavity filled with pus found near the anus or rectum. Ninety percent of abscesses are the result of an acute infection in the internal glands of the anus. Occasionally, bacteria, fecal material or foreign matter can clog an anal gland and tunnel into the tissue around the anus or rectum, where it may then collect in a cavity called an abscess. An anal fistula also commonly called fistula-in-ano is frequently the result of a previous or current anal abscess. Normal anatomy includes small glands just inside the anus. The fistula is the tunnel that forms under the skin and connects the clogged infected glands to an abscess.
This year-old man presented with a very painful infection. There was a large abscess which was easily palpable with surrounding cellulitis. It clearly needed incision so he was admitted for this to be done under general anaesthetic. There was no obvious underlying cause, such as inflammatory bowel disease or diabetes. Following drainage, the abscess cavity required regular dressing but healed well. This man rather sheepishly requested help with the removal of this perianal lesion. It had been present for some years, but his new partner did not like it, making him seek help.
Learn about our expanded patient care options for your health care needs. Most anal fistulas form in reaction to an anal gland that has developed a pus-filled infection abscess. Even if your abscess drains on its own, you have about the same risk for a fistula. Certain conditions that affect your lower digestive tract or anal area may also increase your risk. These include:.
Anal fistula is a chronic abnormal communication between the epithelialised surface of the anal canal and usually the perianal skin. They can form when anal abscesses do not heal properly. Anal fistulae originate from the anal glands , which are located between the internal and external anal sphincter and drain into the anal canal. The tract formed by this process is a fistula.