Anal fissures

Last updated: February 28, 2022

Summarytoggle arrow icon

An anal fissure is a longitudinal tear of the perianal skin distal to the dentate line, often due to increased anal sphincter tone. Anal fissures are classified according to etiology (e.g., trauma or underlying disease) or duration of disease (e.g., acute or chronic). They are typically very painful and may present with bright red blood per rectum (hematochezia). Anal fissures are a clinical diagnosis based on history and examination findings. Management is primarily conservative, and includes stool softeners, analgesia, and possible local muscle relaxation; because of the risk of incontinence, surgical intervention is a last resort.

Primary (due to local trauma)

Secondary (due to underlying disease)

  • Overdistension or disease of the anal mucosa laceration of the anoderm
  • The posterior commissure is believed to have a very poor blood supply, which predisposes it to ischemia (exacerbated by poor perfusion during increased anal pressure).

References:[1]

The rule of anal fissure D's: Distally to the Dentate line; bleeDing During Defecation; Dull puDenDal pain; Diet low in fiber

References:[1][2]

References:[1]

References:[1]

The differential diagnoses listed here are not exhaustive.

Conservative

Interim

  • Persistent symptoms despite > 8 weeks of conservative therapy → endoscopy to exclude IBD
  • If IBD is excluded, then the patient should receive definitive surgical treatment.

Outpatient procedures

Surgical

Conservative therapy is preferred because of the risk of incontinence!
References:[3][4]

  1. Breen E, Bleday R, Weiser M, Friedman LS, Chen W. Anal fissure: Clinical manifestations, diagnosis, prevention. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/anal-fissure-clinical-manifestations-diagnosis-prevention.Last updated: June 8, 2015. Accessed: December 6, 2016.
  2. Poritz LS, Talavera F, Morris DL, Geibel J. Anal Fissure. Anal Fissure. New York, NY: WebMD. http://emedicine.medscape.com/article/196297-overview. Updated: December 16, 2015. Accessed: December 6, 2016.
  3. Ellis CN, Weiser M, Chen W. Anal fissure: Surgical management. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/anal-fissure-surgical-management.Last updated: April 11, 2016. Accessed: December 6, 2016.
  4. Breen E, Bleday R, Weiser M, Friedman LS, Chen W. Anal fissure: Medical management. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/anal-fissure-medical-management.Last updated: May 18, 2016. Accessed: December 6, 2016.

3 free articles remaining

You have 3 free member-only articles left this month. Sign up and get unlimited access.
 Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer