Anal Fissure

  • Kim C. LuEmail author
  • Daniel O. Herzig


An anal fissure is a tear in the anoderm, typically in the posterior midline. In the first 6 weeks, they will likely resolve with increased fiber and water, laxatives, and topical lidocaine. Chronic anal fissures, however, heal only 35.5% of the time without further management. Nearly all treatments seek to relax the hypertonic internal anal sphincter. Perianal topical nitroglycerin, perianal topical diltiazem, and intramuscular (internal anal sphincter) injection of botulinum toxin are slightly more effective than placebo in healing anal fissures. Lateral internal anal sphincterotomy is far more effective (>90%) in healing anal fissure. There is no difference between closed and open sphincterotomy techniques. Atypical anal fissures may require biopsy to rule out infectious disease, inflammatory bowel disease, or malignancy. For patients with hypotonic anal sphincters, dermal advancement flap to close the anal fissure should be considered. This chapter will cover the diagnosis, medical, and surgical management of anal fissures.


Acute anal fissure Chronic anal fissure Topical nitroglycerin or calcium channel blockers Botulinum toxin injection Lateral internal anal sphincterotomy Dermal advancement flap 

Supplementary material

Video 13.1

Anoplasty for anal stenosis. (Courtesy of the American Society for Colon and Rectal Surgeons (ASCRS)) (MP4 100421 kb)

Copyright information

© ASCRS (American Society of Colon and Rectal Surgeons) 2019

Authors and Affiliations

  1. 1.Division of Gastrointestinal and General Surgery, Department of SurgeryOregon Health & Science UniversityPortlandUSA
  2. 2.Division of Gastroenterology and General Surgery, Department of SurgeryOregon Health and Science UniversityPortlandUSA

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