Anal Fissure

Anal Fissure

An anal fissure is a small tear in the thin, moist tissue lining the anus (mucosa). It can occur when passing hard or large stools during a bowel movement. Anal fissures typically cause pain and bleeding during and after bowel movements.

Anal fissures are very common in infants, but they can affect people of all ages. They occur equally in both sexes. Anal fissures can be acute or chronic. They usually appear as a line-shaped tear in the posterior midline anoderm. In women, 10% of fissures are located anteriorly.

Those with anal fissures may experience severe pain after defecation, bright red bleeding (usually on toilet paper), and sometimes itching. Large and solid feces passing through the anal canal can cause fissures. Due to painful defecation, the patient develops secondary constipation (although they may not have had constipation complaints previously). In some patients, the anal sphincter tone increases. Anal sphincter spasm can cause a chronic fissure in the posterior commissure, which has less blood supply and inhibits healing.


The patient history includes pain after bowel movements and a history of bright red bleeding. Anal fissures can easily be seen when the buttocks are spread apart in the Sims or knee-chest position. In chronic anal fissures, the anoderm around the fissure thickens, and muscle fibers of the internal anal sphincter are seen at the base of the fissure. At the outer end of the fistula, a skin tag is visible, and a hypertrophic anal papilla is visible and palpable at the inner end.


The majority of acute anal fissures are treated with simple measures, such as a high-fiber diet, stool softeners (tablets or syrup), and sitz baths. If these treatments do not heal the anal fissure and it becomes chronic, surgery is necessary. Lateral internal sphincterotomy (LIS) is the most commonly performed surgery. It is typically performed on the right side because there is no major hemorrhoidal plexus here. The major hemorrhoidal plexuses are located in the right anterior, right posterior, and left lateral regions.

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