Anorectal Diseases Anal Fissure

An anal fissure is a rectal tear: a tear in the anal canal that causes rectal pain and rectal bleeding. Anal fissure can occur at any age, but are most common in infants: Up to eighty percent of babies develop an anal fissure before their first birthday.

Causes of Anal Fissure

A rectal tear is usually caused by constipation. Bowel movements involving hard, large stools damage the anal canal, causing a longitudinal rectal tear. An anal fissure runs along the length of the anal canal.

Severe diarrhea or anal canal inflammation can also cause anal fissure: Both conditions irritate and dry the anal canal, increasing the risk of a rectal tear.

In elderly individuals, reduced blood flow to the rectal area is one of the causes of anal fissure. Physical trauma and childbirth can also cause rectal tears.

Abuse of laxatives is associated with a high risk of anal fissure. While anal intercourse is one of the least common causes of anal fissure, it can also result in a rectal tear.

Anal Fissure and Rectal Tear Symptoms

Rectal pain and rectal bleeding are the most common symptoms of an anal fissure. Rectal pain is especially intense during bowel movements, when the anal fissure is stretched.

Rectal bleeding due to an anal fissure may be detected as blood in the toilet or on toilet paper following bowel movements. Rectal bleeding caused by a rectal tear will produce bright red blood. Itching may also be present.

The combination of rectal bleeding, rectal pain and itching caused by an anal fissure leads many people to believe they are suffering from hemorrhoids. In fact, hemorrhoids cause rectal pain only when ulcerated or thromosed.

Rectal Bleeding and Anal Fissure Diagnoses

Rectal bleeding can be a sign of many conditions, so careful examination is essential during an anal fissure diagnosis. Physical confirmation of the rectal tear is required to determine the cause of rectal bleeding and pain.

Physical examination of the anal region is usually sufficient to diagnose an anal fissure. In some cases, a small skin flap called a sentinel pile may protrude through the anus.

Rectal Pain Interferes with Anal Fissure Diagnosis

Rectal pain caused by an anal fissure can cause muscle spasms, making visual confirmation of the rectal tear difficult. Additionally, physical examination of the anal fissure can cause excruciating rectal pain. If this is the case, sedation may be required to complete the physical exam.

Unusual Rectal Tears

Most anal fissures are longitudinal: a single tear that runs down the anal canal. A lateral tearan anal fissure that stretches across the anal canalor multiple rectal tears may indicate an underlying health condition. Possible causes of lateral anal fissure include:

  • cancer
  • Crohn’s disease
  • immunosuppression
  • infections
  • inflammatory disorders
  • syphilis
  • tuberculosis.

Treatment of Anal Fissures and Rectal Pain

Anal fissures often resolve by themselves. Those that don’t heal require treatment to assist healing and alleviate rectal pain. Initial treatment may include stool softeners to ease bowel movements and relieve rectal pain. If the anal fissure is infected or appears ulcerated, antibiotics may be prescribed to promote healing.

Self-care for an anal fissure can speed the healing process and alleviate rectal pain. Self-care techniques include:

  • keeping the anus and buttocks area clean
  • patting the anus dry with a soft towel after bathing
  • sitz baths in warm water several times a day.

Sitz bathsbathing the anal regionshould always use warm water, never hot. After bathing, some doctors recommend talcum powder to keep the anal region dry.

Medications for Anal Fissure

Muscle spasms caused by rectal pain prevent the healing of anal fissures. A variety of medications can relax the anal sphincter and prevent muscle spasms, including:

  • botulinum toxin (BOTOX®)
  • l-arginine gel
  • nifedipine
  • salbutamol
  • topical bethanechol
  • topical isozorbide dinitrate
  • topical nitroglycerin.

BOTOX is a relatively new anal fissure treatment. When injected into the anal sphincter, botulinum toxin binds to the sphincter’s presynaptic nerves, temporarily preventing acetylcholine action. Nerve action in the anal region is impaired for up to three months, reducing rectal pain and muscle spasms. BOTOX is effective in up to ninety percent of anal fissure cases, and has only a ten percent likelihood of rectal tear relapse.

Rectal Tear Surgery

Anal fissure surgery is usually reserved for cases where other rectal tear treatments prove ineffective, or if rectal pain is particularly intense. The standard treatment for anal fissure in the United States is a lateral sphincterotomy.

During anal fissure surgery the rectal tear and any surrounding scar tissue is removed from the anal canal. To prevent post-surgical muscle spasms, a small incision is made in the anal muscle.

Complications from anal fissure surgery include slight fecal incontinence in five percent of cases. Some people experience less control over flatulence than they had before the surgery.


Beers, M.H.