Anal Fissure



  • Hard stool passes and “cuts” anoderm
  • Linear tear extends from dentate line to anoderm:
    • Posterior midline 95%
    • Anterior midline 5%
    • Externally: Forms skin tag or sentinel pile
    • Internally: Forms hypertrophied anal papilla
    • Chronic fissure may reveal an ulcer with fibers of internal sphincter with sentinel pile


  • Stress or an overly tight anal sphincter leads to local ischemia of posterior anoderm
  • Diarrhea or hard bowel movement tears anoderm
  • Local trauma from anal intercourse or sexual abuse may be the cause
  • Lateral fissures indicate underlying causative systemic disease:
    • Crohn disease
    • Anal cancer
    • Leukemia
    • Syphilis
    • Previous anal surgery

There's more to see -- the rest of this topic is available only to subscribers.