Anorectal disease refers to ailments of the anus and/or rectum. The most common conditions include hemorrhoids, anal warts, anal fissures, anorectal abscesses and anal fistulas. Hemorrhoids develop when tissues of the rectum and anus become swollen and inflamed. Hemorrhoids can be located inside the anus (internal hemorrhoids) or in the area surrounding the anus (external). Anal fissures are small tears in the lining of the anus. These tears can be caused by hard, dry bowel movements, diarrhea and inflammation. Symptoms include itching, pain and bleeding. Surface fissures heal on their own, but deeper fissures may involve the underlying sphincter muscle in the anal canal and not heal properly. Anorectal Abscess When anal glands become infected, bacteria or fecal matter can enter surrounding tissues and create an anorectal abscess. This infection around the anus or rectum is filled with pus and causes pain, swelling, skin irritation and fever.
Anal Fistula Roughly half of all anorectal abscesses develop into a fistula, an abnormal channel that links infected anal glands to the opening of the skin around the anus. After the abscess has been drained, the passage between the anal gland and the opening in the skin may not always heal. Recurring drainage through the channel can cause fistula formation.