This is a collection of pus in the area around the anus. Infection in the anal region usually arises from small glands in the anal canal. An abscess in the anal area causes pain, which is constant and often severe. There is frequently an area of swelling close to the anus but this is not always apparent. A fever or feeling of being unwell is common. Discharge of pus from the skin or the anus may occur. Surgical drainage is usually performed. In some cases an abscess is associated with an anal fistula.