Anal fistula: causes, symptoms, diagnosis, treatment

A tiny tube can form between the skin and the muscle that surrounds the anus in certain people, and this is known as an anal fistula. It is a sort of abscess that happens when an infection in the anus or rectum does not heal correctly and instead creates a tunnel-like structure.

This can happen in either the male or female reproductive system. An infection in the anal gland, a tiny sac that generates mucus near the anus, is commonly the cause of an anal fistula. Anal glands are located near the anus.


The symptoms of an anal fistula can vary significantly depending on the location of the fistula, its size, and whether or not there is an underlying infection.

The following is a list of common symptoms that may be caused by an anal fistula:

Symptoms including pain or discomfort in the anal region, which may be made worse by sitting or by bowel movements

  • Redness and swelling in the anal region.
  • Pus or blood discharge coming from the fistula.
  • A hump or lump located close to the anus.
  • An uncomfortable sensation of fullness or pressure in the anal region
  • Having trouble keeping bowel motions under control
  • Fever or chills, in the event that an infection is present along with the fistula.


In most cases, an anus or rectum infection that does not heal correctly is to blame for the development of an anal fistula. These infections may be brought on by a variety of different reasons, including the following:

A localized infection in the anus or rectum: When bacteria or other foreign things make their way into the body, this can lead to the formation of abscesses, which are pockets of pus that form while the body’s immune system attempts to fight off the infection.

Abscesses have the potential to grow in either the anus or the rectum, and if they are not treated, they may result in the formation of an anal fistula.

Disease of the inflammatory bowel (also known as IBD): Inflammation in the digestive system, including the anus and rectum, can be brought on by a variety of conditions, including Crohn’s disease and ulcerative colitis. This inflammation has the potential to result in the formation of an anal fistula.

Surgery of the ano or rectal areas: Surgery on the anorectum or rectal region can occasionally result in the formation of an anorectal fistula. This occurs more frequently in procedures that entail the removal of a tumor or an abscess, as well as in situations in which the operation produces a damage to the tissue that surrounds the anus.

Being obese, having a history of anal or rectal infections, and having a weaker immune system are three more variables that may raise the likelihood of developing an anal fistula.

Anal fistula diagnosis

A physical examination and a review of symptoms are usually used to identify anal fistulas. A healthcare physician would often inspect the anus and rectum for obvious evidence of a fistula, such as a lump or bump around the anus, during a physical examination.

The healthcare practitioner may also inquire about particular symptoms, such as anus pain or discomfort, drainage of pus or blood from the fistula, and difficulties managing bowel movements. Additional testing may be required in certain situations to confirm the diagnosis and rule out other illnesses that might produce similar symptoms, such as an abscess or a benign tumour. Among these tests are:

  • Imaging studies: Imaging tests, such as an MRI or CT scan, can aid in the visualisation of the fistula as well as the identification of any underlying abnormalities, such as an abscess.
  • Anoscopy: An anoscopy is a procedure in which a healthcare worker inserts a tiny, illuminated device into the anus to inspect the rectum and anus for abnormalities such as a fistula.
  • Sigmoidoscopy: A sigmoidoscopy is a procedure in which a healthcare practitioner inserts a flexible tube with a camera on the end into the rectum and examines the bottom region of the colon for abnormalities.
  • Colonoscopy: A colonoscopy is a procedure in which a healthcare practitioner inserts a flexible tube with a camera on the end into the rectum and examines the whole colon for abnormalities.


The treatment of an anal fistula often entails either medicinal treatment or surgical surgery. Both of these methods can be equally effective. The precise therapy that is advised will be determined by a number of factors, including the location and size of the fistula, as well as the presence or absence of any underlying infection.

The use of antibiotics to treat any underlying infection and pain drugs to assist control any discomfort that may be experienced are both potential components of the medical therapy of anal fistulas.

A healthcare professional may propose the use of a seton in certain circumstances. A seton is a piece of thread or a thin rubber band that is used to maintain the fistula open and allow for drainage. In some conditions, this may be recommended by the healthcare provider. This can be beneficial in reducing the risk of the fistula closing and getting infected once more.

It is possible that a recommendation for surgical treatment of anal fistulas will be made if medicinal treatment is unsuccessful, the fistula is big or complicated, or both. Anal fistulas can be treated with a number of various surgical methods, including the following:

Fistulotomy: In order to open the fistula and enable drainage, this treatment requires creating an incision in the fistula and cutting through the whole of the fistula.

Placement of a Seton: A seton, which can be a piece of thread or a thin rubber band, is inserted into the fistula during this treatment. The seton is then maintained in place for many weeks in order to keep the fistula open and allow drainage to occur.

Injection of fibrin glue: This method includes injecting a particular adhesive into the fistula in order to close it and make it inaccessible to bacteria.
This operation involves tying off the fistula and draining any pus or infected fluid that is coming from it. It is called “ligation and drainage.”

The fistula is closed using a technique known as “fistula plugging,” which includes putting a plug composed of tissue or a synthetic substance into the fistula in order to shut it.
It is essential to collaborate with a healthcare expert in order to ascertain which treatment method would be most effective for your unique circumstance.

Precautions to be Taken to Prevent Anal Fistula

You may assist lower your chance of having an anal fistula by taking a few different actions, including the following:

Maintain a high level of hygiene: Maintaining cleanliness in the anal region can aid in the prevention of infections, the presence of which can contribute to the development of an anal fistula.

Visit the restroom as soon as you become aware of the need to do so: The faeces can become hard and difficult to pass if you hold in your bowel movements, leading to pressure and irritation in the anal area, which can raise the risk of developing an abscess or a fistula. This increases the chance of getting an abscess or a fistula.

Consume a diet that is high in fiber: Constipation, which can place excessive strain on the anal region and increase the chance of developing an abscess or fistula, can be prevented, at least in part, by eating a diet rich in fiber.

Make sure you get lots of fluids: Maintaining a healthy level of hydration can assist in the avoidance of constipation and contribute to an overall improvement in digestive health.

Regular exercise can assist improve bowel movements and minimise the risk of constipation. Regular physical activity can help improve bowel movements.

Avoid smoking since it can reduce the effectiveness of the immune system and increase the likelihood of getting infections, especially those that occur in the anus or rectum.

Seek medical assistance if you have any symptoms in the anal or rectal area If you experience any symptoms in the anal or rectal area, such as pain, swelling, or discharge, it is crucial to consult a healthcare practitioner in order to receive an accurate diagnosis and appropriate treatment.

Ignoring these symptoms might raise the likelihood of developing an anal fistula, which can be quite serious.[1]Microsoft Word – Anal Fistula.doc ([2][3][4]Anal Fistula – Risk Factors – Clinical Features – TeachMeSurgery[5]Modern management of anal fistula (

Reviewed by:

Dr. Amjad Hayyat


Medical specialist

Makhdoom medical complex, Sargodha, Pakistan

For our experts information click here


1Microsoft Word – Anal Fistula.doc (
4Anal Fistula – Risk Factors – Clinical Features – TeachMeSurgery
5Modern management of anal fistula (

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