A sphincterotomy is a procedure performed to treat anal fissures. An anal fissure is a split in the lining of the rectum, possibly resulting from a hard bowel movement. Muscle spasms and subsequent bowel movements prevent healing. Fissures can be encouraged to heal using topical medications and stool softeners, but severe or recurring fissures may require a sphincterectomy.
During a sphincterotomy, the outermost part of the anal sphincter is cut. This weakens the muscle and relieves the muscle spasms which prevents healing. A sphincterotomy may be performed in a hospital or clinic.