Lateral Internal Sphincterotomy

Anal fissure, or fissure-in-ano, is a common pathology that can be significantly distressing and potentially disabling among affected individuals. Initial management of anal fissures encompasses conservative measures such as a stool bulking agent and sitz baths. Additional symptom relief may be achieved with stool softeners, topical anesthetics, topical nitrates or calcium channel blockers, and botulinum toxin injections. Patients with anal fissures that persist beyond 6 weeks (i.e., chronic fissures) despite optimal nonoperative treatment may be candidates for lateral internal sphincterotomy (LIS). LIS is the treatment of choice among those with chronic fissures and in the absence of fecal incontinence among other risk factors (e.g., prior obstetrical injury, prior anorectal operations, inflammatory bowel disease, or weak sphincter). Most commonly performed in the outpatient setting, LIS is associated with minimal morbidity and high long-term success rates.