Anal fistula: causes, diagnosis and treatment


A slot in the end of the gastrointestinal tract, function of its output of waste and solid objects resulting from the process of digestion.

There is a group of muscles to move the report energizes the anus, and the circular muscles of the figure belong to the sphincter of the rectum, which is the quality of the interior which is controlled by unconscious effort and external that is controlled involuntarily, and the dual function is maintained and the incisional hernia and let in waste during defecation.

Anal fistula

A channel, hollow or cavity of abnormal links between the opening inside the anal canal and secondarily in the skin around the anus.

Types of fistula

Classify the types of anal fistula according to its position, it will be mentioned in order from most common to least common, include:

  • A fistula between the LED intersphincteric: the channel of the fistula between the muscles of the internal sphincter and external opening near the anus, and 70% of all types of anal fistula.
  • Nassau across the valve: start channel of the fistula in the internal sphincter and then the expression of the muscle external opening outside the anus, and include a 25%.
  • Nassau above the valve: it begins in the void between the internal sphincter and external and it is up to the highest point of the muscle, bone, crosses this muscle, then extends downward between the muscles of the pubic to the anal muscle cranes, preferably outside of the anus, and includes the 5%.
  • Nassau outside of the valve.: The device starts at the rectum and extends to the bottom and passes through the levator muscle and opens around the anus. Usually the cause of this fistula abscess, appendicitis, abscess, diverticulum, or Crohn’s disease. Constitutes 1% of all anal fistulas.

The causes of fistula anal

The main causes of fistula anal are clogged anal gland abscesses anal. In addition to cases other less common which can cause nor an enema:

  • Crohn’s disease (inflammatory bowel disease).
  • Radiation (cancer treatment).
  • Sexually transmitted diseases.
  • TB.
  • Diverticulosis (a disease that share the small bags in the large intestine and inflammation).
  • Cancer.

The symptoms of anal fistula

Include signs and symptoms of anal fistula:

  • Abscesses anal repeated.
  • Pain and swelling around the anus.
  • The exit of pus, bloody or foul-smelling of autumn.
  • Irritation of the skin around the anus from the exit of the pus.
  • Pain with a bowel movement.
  • Bleeding.
  • Fever and chills and a general feeling of fatigue.


It is usually easy to locate the external opening of fistula anal, while locating the inner shaft may be more difficult. It is important to be able to find the fistula, the whole of effective treatment.

Gives the position of the aperture of the external evidence of the likely path for birds. In simple cases, can help rule Goodsall in the forecast, the legislative process for the public. Which states that the presence of the opening of the fistula to the anus means that the track of the fistula passes straight to the inside of the anal canal, and opening of the fistula and behind the anus means that the area of the fistula is curved to the inside of the anal canal.

Tools often used in diagnosis include:

  • Probe fistula, which is a tool specifically designed to be inserted through the fistula.
  • Anoscope, a small tool to export the anal canal.

If the fistula is in place is not supported, you can use these tools too:

  • Dye methylene blue diluted by injected into the fistula.
  • The filming of the fistula by the injection of a solution into the fistula and then photographed X-ray.
  • Magnetic resonance imaging.

Tools used to rule out other disorders such as ulcerative colitis or Crohn’s disease include:

  • Flexible sigmoidoscopy, which allows the introduction of narrow, flexible tube fitted with camera is lit inside edge, which allows doctors to see the lining of the rectum and sigmoid colon as a magnified on a TV screen.
  • Colonoscopy is similar to sigmoidoscopy, but with the ability to examine the entire colon or large intestine.

Treatment of anal fistula

Treatment is performed carefully to minimize the risk of impact on output in the future, due to the anal fistula of the muscles of the anal sphincter.

Cut fistula Fistulotomy:

The surgeon first looks to find the inner shaft for the audience, then cut the channel and scraped it off on the scan its contents out, then stitches are aspects in order to open the fistula. Had surgery is performed on more than one stage if you must cut a large amount of muscle. It may be necessary to repeat the surgery if you cannot find the whole channel.

Tinkering with rectal Advancement Rectal Flap:

The surgeon will take the patch of the wall of the rectum to reach the aperture of the internal fistula removed. This is often done to reduce the amount of sphincter to be cut.

Put the basket will be the Seton Placement:

Is used basket will be a series of silk or elastic band to either:

  • The innovation of the scar around the sphincter muscle before cutting it with a knife.
  • Or let the lady with the fistula through the muscle slowly over the course of several weeks.

G fibrin or plug of collagen loss after an injury Glue or Collagen plug:

In some cases, you can use the grams of fibrin, made from plasma protein, to close the fistula there instead of cutting it. Is injected the glue through the external opening after clearing the channel and sew the hole closed.

Can also use a plug of collagen protein to close the course of the fistula.


UCSF Department of Surgery (2019) Anal Fistula, Available at: (Accessed: 23/12/2019).

Cleveland Clinic (2019) Anal Fistula, Available at: (Accessed: 23/12/2019).

Juan L Poggio, (2018) Fistula-in-Ano, Available at: (Accessed: 23/12/2019).

0 Comments on “Anal fistula: causes, diagnosis and treatment”

  1. Hola I all the time used to read article in news papers but now as I am a user of net thus from now I am using net for content, many thanks

Leave a Reply

Your email address will not be published. Required fields are marked *