gastrointestinal disorders
Anal Fissure
Introduction
An anal fissure is an acute longitudinal tear or a chronic ovoid ulcer in the squamous epithelium of the anal canal. It causes severe pain, sometimes with bleeding, particularly with defecation. Diagnosis is by inspection. Treatment is local hygiene, stool softeners, topical measures, and sometimes botulinum toxin injection and/or a surgical procedure. (See also Evaluation of Anorectal Disorders .) Anal fissures are believed to result from laceration by a hard or large stool or from frequent loose bowel movements. Trauma (eg, anal intercourse) is a rare cause. The fissure may cause internal sphincter spasm, decreasing blood supply and perpetuating the fissure. 