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.
Anal Fissures are tears in the skin around the anus. They are usually caused by severe constipation, with passage of hard stool along with straining tears the skin. They can be very painful, usually described as sharp burning or tearing pain while having a bowel movement. The pain is primarily due to spasms in the nearby sphincter muscle. Most anal fissures will heal on their own with proper bowel management.
The anus is that part of the intestinal tract that passes through the muscular canal of the pelvis and anal sphincters. It is the final orifice through which stool passes out of the body. In adults, the anus is 4 to 5 centimeters long. The lower half of the anal canal has sensitive nerve endings.