• Pathology
• Etiology & Pathogenesis
• Pathophysiology
• Epidemiology
• Management & Treatment
• Prevention
• Complications
• Prognosis
• Research Frontier
• Clinical Case Studies
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• 
  Symptoms
• Risk Factors
• Diagnosis
• Treatment
• Complications
• Prevention
• When to Seek Care

Anal fissures are tears or cracks in the anus. Fissures result from stretching the anal mucosa beyond its normal capacity. Once the tear occurs, it leads to repeated injury. The exposed internal sphincter muscle beneath the tear goes into spasm. This causes severe pain. The spasm also pulls the edges of the fissure apart, making it difficult for the wound to heal. The spasm then leads to further tearing of the mucosa during bowel movements. This cycle leads to the development of a chronic anal fissure in approximately 40 percent of patients.

An acute anal fissure typically heals within six weeks with conservative treatment. Some disappear when constipation is treated. Anal fissures that last for six weeks or more are called chronic anal fissures. These fail conservative treatment and require a more aggressive, surgical approach.

Fissures are sometimes confused with hemorrhoids. Hemorrhoids are inflamed blood vessels in, or just outside, the anus. Both fissures and hemorrhoids often result from passing hard stool.