Acute suppurative infection occurs in the soft tissue around the anal canal and rectum or in the space around it, and an abscess is formed, which is called an anal canal and rectal abscess. It is characterized by spontaneous rupture, or the formation of anal fistula after surgical incision and drainage. It is a common anorectal disease, and it is also the acute stage of the pathological process of anal canal and rectal inflammation, and anal fistula is the chronic stage. Common pathogens include Escherichia coli, Staphylococcus aureus, Streptococcus and Pseudomonas aeruginosa, occasionally anaerobic bacteria and Mycobacterium tuberculosis, and it is often a mixed infection of multiple pathogens. The ischiorectal fossa is more common, and is mostly caused by the spread of anal gland infection through the external sphincter to the ischiorectal space.