1 Etiology of atypical fissures includes Crohn's disease, ulcerative colitis, anal cancer, tuberculosis, HIV, syphilis, herpes, and leukemia. 1 Less than 1% of all fissures are located off of the midline position and these are considered atypical fissures. Approximately 25% of fissures are in the anterior location and these are more common in women. The most common site for males and females is the posterior midline, greater than 75% occur in this location. 1 Fissures may also occur in children and the elderly. Fissures are most commonly seen in middle-aged and younger patients, with mean age of onset 39.9 years.

10įissures are seen with equal frequency in males and females. This could explain the sphincter spasm and pain that patients with anal fissure experience with defecation. In patients with anal fissures, there is evidence that the rectoanal inhibitory reflex is followed by an abnormal increased contraction. 3 4 5 6 7 8 9 This hypertonicity of the anal sphincter is responsible for some of the pain and spasm experienced with defecation, and it also has a deleterious effect on wound healing by reducing blood flow to the traumatized anoderm. Several studies have shown that the resting pressure of the internal anal sphincter is higher in patients with fissures compared with normal controls. As a response to the fissure, patients typically experience increased pressure within the anal canal.

This includes trauma to the anoderm during the passage of hard or large bowel movements, local irritation from diarrhea, anorectal surgery, and anoreceptive intercourse. The exact cause of an anal fissure is not entirely clear, but it is thought to result from trauma to the anal canal.

Sentinel pile treatment