Anal stenosis is a rare but serious complication of anorectal surgery, most commonly seen after hemorrhoidectomy. Anal stenosis represents a technical challenge in terms of surgical management. A Medline search of studies relevant to the management of anal stenosis was undertaken. The etiology, pathophysiology and classification of anal stenosis were reviewed.

Although treatment with either topical nitroglycerin or botulinum toxin is effective as an alternative to surgery for patients with chronic anal fissure, botulinum toxin is the more effective option.

Botulinum toxin injections should be considered as a simple therapeutic approach in patients with obstructed defecation. The treatment is safe and effective, especially with the use of the ultrasonographic guidance that accounts for a more precise injection and consequently better long-term results. Otherwise, given the limited effect of the toxin, repeated injections may be necessary to maintain the clinical improvement.

Regarding postoperative surgical complications, end-to-side anastomosis is a safe procedure.