An anal fissure is a tear in the skin of the anal canal. A fissure most commonly occurs from the trauma of passing a large bowel movement or repeated bowel movements as a result of diarrhea. Occasionally a fissure may be a manifestation of an underlying disease such as Crohn’s Disease.


The most common symptom associated with an anal fissure is pain with having a bowel movement. Bright red blood may also be noted on the stool and toilet paper with wiping.


An anal fissure is usually diagnosed by physical examination or by inspecting the anal canal with a tube called an anoscope.


The fissure will often heal spontaneously over several weeks. Symptomatic treatment with Sitz baths, stool softeners, and painkillers may be helpful. Medications such as nitroglycerin or calcium channel blockers, which relax the anal sphincter and promote healing, are also often effective. An injection of Botulotoxin into the anal sphincter may also promote healing. Fissures that become chronic or fail to respond to these therapies may be cured through surgery. This typically involves excising the fissure and carefully loosening the sphincter muscle to promote healing.