Anal Fissure

(Fissure in Ano; Anal Ulcer)

ByParswa Ansari, MD, Hofstra Northwell-Lenox Hill Hospital, New York
Reviewed/Revised Jan 2023

An anal fissure is a tear or ulcer in the lining of the anus (the opening at the end of the digestive tract where stool leaves the body).

  • Anal fissures may occur after passage of hard or large bowel movements.

  • Symptoms include pain or bleeding during or after a bowel movement.

  • The diagnosis is based on an examination of the anus.

  • Treatment includes stool softeners, protective ointments, and sitz baths and sometimes botulinum toxin injection or a surgical procedure.

Anal fissures may be caused by an injury from a hard or large bowel movement or from frequent loose bowel movements. Rarely, they may also be caused by penetration of the anus during anal sex.

Fissures cause the anal sphincter (the muscular ring that keeps the anus closed) to go into spasm, which worsens pain and prevents healing.

Anal fissures can occur in people of any age but are most common among infants.

(See also Overview of the Anus and Rectum.)

Symptoms of Anal Fissure

Fissures cause pain and bleeding, usually during or shortly after a bowel movement. The pain lasts for several minutes to several hours and then subsides until the next bowel movement.

Anal Fissure
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This photo shows an anal fissure.

Diagnosis of Anal Fissure

  • A doctor's examination

A doctor diagnoses a fissure by gently inspecting the anus.

Treatment of Anal Fissure

  • Stool softeners and fiber

  • Protective ointments and sitz baths

  • Botulinum toxin injection or nitroglycerin ointment or calcium channel blockers

A stool softener and fiber supplements or increased dietary fiber may reduce the possibility of injury by hard or large bowel movements.

If these measures do not work, surgery may be needed. To relieve sphincter spasms, doctors cut a portion of the internal sphincter (called internal anal sphincterotomy).

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