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  • Fissure: Split in the anoderm

    Ulcer: Chronic fissure

    • Associated with skin tag (sentinel pile) once matured

    • Located in midline, distal to dentate line

    • Most commonly located posteriorly (90%)

    • Caused by forceful dilatation of anal canal, usually from defecation, leading to sphincter spasm and local anoderm ischemia


  • • Predisposing factors: previous anorectal surgery (hemorrhoidectomy, fistulotomy)

    • Classically, initial insult is a firm, hard bowel movement

    • -Pain resulting from the initial bowel movement may be great, leading to tendency to resist urge to defecate

      -This leads to the formation of harder stool

Symptoms and Signs

  • • Pain and bleeding with defecation

    • Pain may be tearing or burning, worst during defecation, may last for hours

    • Blood may be noted on tissue or on stool but not mixed in

    • Constipation may develop secondary to fear of recurrent pain

    • May present as painless, nonhealing wounds that occasionally bleed

    • Physical exam reveals disruption of anoderm in the midline at the mucocutaneous junction

    • Sentinel skin tag or pile may be present at the inferior margin

    • Digital exam may reveal sphincter spasm

Laboratory Findings

  • • No specific findings

    • Anal manometry may demonstrate increased sphincter tone

Imaging Findings

  • • No specific findings

  • • Crohn disease

    • Anal tuberculosis

    • Anal malignancy

    • Abscess

    • Fistula

    • Cytomegalovirus

    • Herpes

    • Chlamydiosis

    • Syphilis

    • AIDS

Rule Out

  • • Anal malignancy

  • • History (including previous anorectal surgery) and physical exam

    • Following diagnosis, patients should undergo anoscopy and sigmoidoscopy to evaluate for anorectal malignancy or inflammatory bowel disease

    • Nonhealing ulcers should be biopsied

When to Admit

  • • Rarely, except for severe pain or bleeding leading to hemodynamic compromise, or both

  • • Initial treatment is conservative with stool softeners, bulking agents, sitz baths



  • • Failure of conservative measures

    • Perform lateral internal anal sphincterotomy


  • • 0.2% nitroglycerin ointment

    • Botulinum toxin infiltration into internal sphincters may aid healing

    • Stool softeners

    • Bulking agents

Treatment Monitoring

  • • Follow-up physical exam


  • • Sphincterotomy may result in fecal incontinence

    • Recurrence


  • • Conservative measures will result in healing in 90% cases

    • A second episode has a 70% chance of healing with conservative treatment

    • Lateral internal anal sphincterotomy is over 90% successful

    • Recurrence rate is less than 10% after sphincterotomy


Altomare DF et al: Glyceryl trinitrate for chronic anal fissure: healing ...

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