Anal Fissure

An anal fissure is a laceration or crack in the lining of the anus that extends to the circular muscle. Acute fissures usually heal spontaneously or with minimal treatment. Chronic fissures recur and may require surgery. The prognosis is good, especially with fissurectomy and good anal hygiene.

Posterior fissure, the most common form, is equally prevalent in males and females. Anterior fissure, the rarer type, is 10 times more common in females.

Causes

Anal fissures are extremely common in young infants but may occur at any age. Studies suggest 80% of infants will have had an anal fissure by the end of the first year. Most fissures heal on their own and do not require treatment, aside from good diaper hygiene. However, some fissures may require medical treatment.

The incidence of anal fissures decreases rapidly with age. Fissures are less common among school-aged children than among infants.

In adults, fissures may be caused by constipation, the passing of large, hard stools, or by prolonged diarrhea. In older adults, anal fissures may be caused by decreased blood flow to the area.

Anal fissures are common in women after child birth and people with Crohn's disease .

Signs and Symptoms

Typically, the patient complains of pain, which he describes as tearing, cutting, or burning, during or immediately after a bowel movement. He may also report blood on his underclothes or toilet paper.

In the patient with chronic fissure, additional signs and symptoms may include dysuria, pruritus, and urinary frequency or urine retention. The patient may also complain of painful anal sphincter spasms that result from ulceration of "sentinel pile" (swelling at the lower end of the fissure).

Gentle traction on the perianal skin can create sufficient eversion to visualize the fissure directly. Digital examination permits palpation of the fissure. Keep in mind that a digital examination can elicit pain and bleeding.

Diagnostic tests

Anoscopy showing longitudinal tears helps to confirm the diagnosis.

Barium enema and sigmoidoscopy are performed to rule out inflammatory bowel disease if the patient has painless or multiple fissures.

Treatment

Management of an acute fissure provides local pain relief with analgesics, sitz baths, and bulk-producing agents, such as psyllium. Soft stools prevent further tearing and decrease pain associated with defecation. Intra-anal application of isosorbide dinitrate ointment over 6 to 12 weeks is successful in most patients. If further treatment is required, the fissure may be removed by surgical excision (fissurectomy).

Prevention

To prevent anal fissures in infants, be sure to change diapers frequently. To prevent fissures at any age:

• Keep the anal area dry
• Wipe with soft materials
• Promptly treat any constipation or diarrhea
• Avoid irritating the rectum