Am Fam Physician. 2016 Mar 15;93(6):498-499.
Author disclosure: Richard L. Nelson has received fees from the American College of Physicians for web-based education modules. He is also the author of references cited in this review.
Chronic anal fissures typically occur in the midline, with visible sphincter fibers at the fissure base, anal papillae, sentinel piles, and indurated margins.
Anal fissures are a common cause of anal pain during and for one to two hours after defecation. The cause is not fully understood, but low intake of dietary fiber may be a risk factor.
Chronic fissures typically have a cyclical history of intermittent healing and recurrence, but about 35% will eventually heal, at least temporarily, without intervention.
Atypical features, such as multiple, large, or irregular fissures, or those not in the midline, may indicate underlying malignancy, sexually transmitted infections, inflammatory bowel disease, or trauma.
Internal anal sphincterotomy is more effective than medical therapy for chronic anal fissure in adults. It improves fissure healing compared with treatment with nitric oxide donors (topical nitroglycerin, topical isosorbide dinitrate), botulinum A toxin–hemagglutinin complex, and calcium channel blockers (nifedipine, diltiazem).
Internal anal sphincterotomy also increases fissure healing compared with digital anal stretch, and anal stretch is more likely to cause flatus incontinence. One small randomized controlled trial found limited evidence that controlled anal dilation may be equivalent to sphincterotomy in fissure healing, with negligible incontinence risk.
We do not know whether anal dilation is more effective than topical nitroglycerin at reducing the proportion of persons with anal fissure.
We do not know whether internal anal sphincterotomy is better or worse than anal advancement flap in improving fissure healing.
Open partial lateral internal anal sphincterotomy may be equivalent to closed partial internal anal sphincterotomy in fissure healing.
Longer internal anal sphincter division (to the dentate line, as opposed to the fissure apex only) may be more effective at reducing anal fissure.
The risk of minor flatus or fecal incontinence is greater with internal anal sphincterotomy than with botulinum toxin. Topical nitroglycerin
This is one in a series of chapters excerpted from the Clinical Evidence Handbook, published by the BMJ Publishing Group, London, U.K. The medical information contained herein is the most accurate available at the date of publication. More updated and comprehensive information on this topic may be available in future print editions of the Clinical Evidence Handbook, as well as online at http://www.clinicalevidence.bmj.com (subscription required).
This series is coordinated by Kenny Lin, MD, MPH, Associate Deputy Editor for AFP Online.
A collection of Clinical Evidence Handbook published in AFP is available at http://www.aafp.org/afp/bmj.
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