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. Fistula is a tunnel that connects a clogged gland inside the anal canal to the outside skin.
This is an infection that appears as a tender red lump under the skin near the anus. This lump can grow large and become painful. This type of abscess happens most often in babies and children under a year of age. It may drain fluid pus on its own and then heal and disappear.
NCBI Bookshelf. Perianal abscesses are the most common type of anorectal abscesses. These abscesses can cause significant discomfort for patients.
An anal, or rectal, abscess occurs when a cavity in the anus becomes filled with pus. It causes extreme pain, fatigue , rectal discharge, and fever. In some cases, anal abscesses can result in painful anal fistulas. A blocked anal gland, a sexually transmitted infection STI , or an infected anal fissure can cause anal abscesses. Some other risk factors include:.