Anal operations, including hemorrhoidectomy, excision of anal fissure and lateral subcutaneous internal sphincterotomy, drainage of a perianal or ischiorectal abscess, anal fistulotomy, excision of condyloma acuminata, and excision of recurrent squamous cell carcinoma or perianal skin squamous carcinoma are among the most common operations performed by general surgeons.

Hemorrhoids are abnormally dilated veins of the hemorrhoidal venous plexus that are classified according to their location above (internal) or below (external) the dentate line. Most hemorrhoids cause minimal symptoms and are managed by sitz baths, topical anesthetics, stool softeners, and a high-fiber diet. In the absence of contraindications such as inflammatory bowel disease, portal hypertension, blood dyscrasias, local cellulitis, and uncontrollable diarrhea, hemorrhoidectomy is indicated for patients with persistent bleeding, pain, or prolapse. Patients with contraindications to operation are treated with injection of sclerosing agents or rubber band ligation (internal hemorrhoids only).

Fissures are usually posterior acute or chronic ulcers that cause painful defecation. Operative therapy is performed less frequently at this time because of the wide range of alternate therapies that relax the internal anal sphincter and promote healing. Included among these are the topical application of 1% isosorbide dinitrate ointment, 2% diltiazem cream, 1% bethanechol cream, or 2% glyceryl trinitrate ointment. Another conservative approach is the injection of 20 units of Botulinum toxin Type A into the internal sphincter muscle.