Dr. Weyrich's Naturopathic Functional Medicine Notebook is a collection of information on topics of interest to Dr. Weyrich that may be of interest to the world wide audience. Due to limitations of time, not all information that Dr. Weyrich knows or would like to further research is published here. Dr. Weyrich welcomes financial contributions to support specific research topics, as well as copies of non-free access journal articles for him to review on a topic. Constructive criticism is also welcome.


Overview of Anal Fissure (Fissure-in-Ano)

Anal fissures (fissure-in-ano) are tears in the skin and mucosa of the anal canal that cause a knife-like pain during and after bowel movement.

Signs and Symptoms of Anal Fissure (Fissure-in-Ano)

  • Sharp or stabbing anal or rectal pain, especially during stool.
  • Rectal bleeding.
  • Blood in stool.
  • Anal itching.
  • A "sentinel pile" or skin tag may be observed distal to the location of the fissure.

Etiology of Anal Fissure (Fissure-in-Ano)

Constipation leading to the passing of hard stools may tear the skin, as may the passing of sharp shards such as seed shells. Diarrhea and frequent overly exuberant wiping or other mechanical damage can also abrade the anal canal.

Tight anal sphincter muscle tone may reduce blood circulation to the tissues of the anal canal, leading to less healthy, more easily torn tissues that are more susceptible to mechanical damage. The pain caused by the resulting anal fissure causes further tightening of the sphincter, creating a self-perpetuating cycle of pain and injury.

Less commonly, other causes of anal fissures include diseases such as Crohn's disease, leukemia, syphilis, TB, or HIV.


Diagnosis of Anal Fissure (Fissure-in-Ano)

Diagnosis is by case history and physical exam. Careful spreading of the buttocks normally allows visualization of the fissure. If a fissure is visualized, anoscopy is not indicated. If this maneuver does not allow visualization, anoscopy with a small caliber anoscope that is lubricated with lidocaine ointment, gentle palpation with a lubricated finger, or endoscopy may be required for diagnosis.

Chronic fissures may give rise to an external skin tag called a sentinel pile inferior to the fissure, an enlarged papilla superior to the fissure, and white fibrous scar tissue along the path of the fissure. Muscle fibers may be visible in the trough of the fissure.

Fissures are normally long and narrow with sharply demarcated borders. Other shapes should raise suspicion of other causes (see DDX).

The most common locations of fissures due to physical abrasion are the posterior and anterior midlines, and occur singly. Multiple fissures or fissures located in other areas should raise suspicion of other causes (see DDX).


Differential Diagnosis of Anal Fissure (Fissure-in-Ano)


Treatment of Anal Fissure (Fissure-in-Ano)

Treatment principles include:
  • Correct constipation or diarrhea.
  • Follow good anal hygiene.
  • Reduce anal sphincter tone. Topical nitrates (nitroglycerine) or calcium channel blockers may be used for this purpose. A common side effect of nitrates is headaches. Botulinum toxin has also been used to reduce muscle tone, but may result in temporary incontinence.
  • Sooth tissues and relieve inflammation, using for example corticosteroid suppositories and creams.
  • Relieve pain with analgesic or anesthetic creams.
  • Promote blood flow to heal tissues.
  • Surgically remove chronic scar tissue to allow normal healing.
  • Rule out further pathology with colonoscopy or sigmoidoscopy.

In about half the cases, conservative treatment may resolve anal fissures. In the remaining cases, surgical intervention is necessary.

Surgical treatment of chronic fissures involves using electrodessication or chemical cautery with silver nitrate to shave off scar tissue to allow regrowth of healthy tissue. Associated enlarged papillae, hemorrhoids, and sentinel piles may also need to be surgically treated.

Post-surgical pain may temporarily exceed the pain of the fissure itself, with complete remission of pain expected over a period of a couple months.

While most patients will get lasting relief from the above treatments, more aggressive treatments such as referral for lateral partial internal sphincterotomy to reduce sphincter tone may be considered.


Prevention of Anal Fissure (Fissure-in-Ano)

Correct constipation or diarrhea and follow good anal hygiene.

Sequelae of Anal Fissure (Fissure-in-Ano)

Non-surgical treatment of chronic fissures has about a 40% failure rate.

Untreated fissures may be associated with cryptitis, abscess or fistula formation.


ICD-9 Codes related to Anal Fissure (Fissure-in-Ano)

ICD9-CodeDescriptionComments
565.0Anal fissure 
564.6Anal spasm 
569.3Anorectal bleeding, unspecified origin 
569.42Anorectal pain, unspecified origin 

References for Anal Fissure (Fissure-in-Ano)