Skip to content


It is known as a fistula to block the exit of one or more glands of the anus. Thus, an abscess is formed that breaks the skin around the anus, thus giving rise to an abnormal connection between the inside and outside of the anal canal. A correct diagnosis of the abscess prior to the appearance of the fistula could prevent around 50% of cases.

Generally, an anal fistula arises as a result of an infection that begins in the anal gland. As a consequence, the infection forms an abscess, which in turn leads to the formation of the fistula.

Anal fistula

The anal fistula is a relatively common disorder among people older than 50 years. It is characterized by the formation of a tube under the skin that is around the anus. This duct has an external hole, located in the skin of the anus, and an internal hole, which is located inside the anus or rectum. In certain cases, the duct has a complex shape due to an anal abscess, which means that there is no communication between both ends of the duct.


  • Blind: they are known as such to those fistulas that are open only at one end, but connect two structures.
  • Complete: are those that have openings at both ends.
  • Horseshoe: in this case the fistula connects the anus with the anal opening after surrounding the rectum.
  • Incomplete: and, finally, incomplete fistulas, in which a tube closed inside does not connect with any structure.


The causes of an anal fistula can be very diverse. Those that occur most frequently are the following.

  • Abscess – This is the most common cause of an anal fistula. An abscess usually forms from a collection of pus from infection from an anal fissure.
  • Crohn’s disease : Although it is not a cause in itself of anal fistula, Crohn’s disease does pose a very important risk factor. It is a chronic inflammatory process located in the intestine.
  • Ulcerative colitis: This is an inflammatory disease characterized by the formation of ulcers in the digestive tract, especially in the colon and rectum.
  • Anorectal cancer: a malignant tumor that affects the anus and rectum, the main symptoms of which are localized pain in the area and rectal bleeding.
  • Anal sex : practicing anal sex is one of the main risk factors for the formation of a fistula in this area of ​​the body. It is important to have safe sex with adequate protection.


When it comes to anal fistula symptoms, they are relatively easy to identify. In the vast majority of cases, there is severe pain in the anus area , which worsens when sitting or doing any type of physical effort. There is also the presence of pus, which becomes noticeable when defecating.

The pus can irritate the skin around the anus, leading to symptoms such as itching, stinging, and redness in the area.

Also, if the anal fistula has been formed by an abscess , there is most likely a red, hard-textured lump in the anal area.

Diagnosis and treatment

Given the symptoms described in the previous section, it is important to see a doctor as soon as possible. Once the medical history has been made based on the indicated indications, the doctor will proceed to carry out a physical examination to look for the presence of abscesses .

The presence of fistulas can not always be determined with a visual examination. In these cases the doctor will proceed to perform a rectal examination. The most common is that this test is done with the help of an anoscope, which allows you to see the inside of both the anus and the rectum, as well as take tissue samples.

Currently the only truly effective treatment for an anal fistula is surgery. It is a relatively simple operation in which the fistula is permanently removed and any abnormalities that it may have caused are treated.

perianal fistula

The perianal fistula is known as the communication that exists between the anal canal and the skin at the exit of the anus. It is a relatively common disorder, especially in men over 50 years of age. The communication is called a fistulous path ; its origin is in glands located inside the anal canal, from where it passes through the sphincters of the anus to the external orifice. Thus, the secretion of pus and even feces occurs through said communication.

The perianal fistula arises because of the obstruction of the glands responsible for the lubrication of the anal canal, thus favoring the accumulation of germs.

In many cases this type of fistula does not present any type of symptoms in its initial stages, so that the medical diagnosis is determined in late phases, thus making the treatment more complex. The most common signs are: severe pain in the area, irritation in the skin around the anus , discharge of pus and fever in case of infection.

The only really effective treatment at present is surgical intervention. Although there are several medications that relieve symptoms to some extent, the only definitive option is surgery . Perianal fistulas that cross the sphincter are very complex since if the incision is made incorrectly, the patient could suffer from chronic fecal incontinence.

Arteriovenous fistula

The arteriovenous fistula is what is known as an abnormal connection that exists between the artery and the vein. Generally, the blood flow runs through the arteries to the capillaries, from where the blood travels to the veins. Well, when there is a fistula of this type, the blood flows directly into the vein, thus avoiding some capillaries.

When this happens, the tissue under the capillaries does not get enough blood. Although arteriovenous fistulas occur especially in the legs, they can occur anywhere in the body.

There are a number of risk factors that somewhat increase your chances of developing arteriovenous fistula: hypertension, obesity , advanced age, and the use of certain blood-thinning medications.

The symptoms of this type of fistula are especially noticeable: bruised veins that in some cases can even protrude and be seen through the skin, inflammation of the affected area , decrease in blood pressure, fatigue, and heart failure. In the presence of one or more of these symptoms, it is important to see a doctor as soon as possible to make the appropriate diagnosis.

Difference: fistula and hemorrhoids

Although sometimes fistula and hemorrhoids are treated as the same, the truth is that they are two very different disorders from each other.

The main defining characteristic of an anal fistula is the suppuration of yellowish-white pus. The pain is not directly related to bowel movements, and is relieved when the infection is drained.

Meanwhile, hemorrhoids give rise to anal bleeding and, in addition, the patient may notice the exit of a lump after defecation if the hemorrhoids are external.


Surgical intervention is essential to permanently eliminate the anal fistula . In the vast majority of cases, local anesthesia is used, although if the fistula is more complex, general anesthesia may be necessary.

In general, the operation lasts approximately one hour, although it may vary depending on the characteristics of the fistula and the complications that have arisen from it. Non-invasive techniques are now being introduced that are more beneficial.

Once the intervention is finished, the patient is transferred to the resuscitation room. The medical team will then explain to you how you should perform the dressings and sitz baths during the recovery process.

Fistula prevention

There are a number of factors worth remembering to prevent anal fistulas in adults.

  • Constipation : one of the most common causes of fissure formation in the anus is constipation. That is why it is so important to follow a balanced diet, favoring the consumption of fruits and vegetables rich in fiber. In this way, intestinal transit is improved. It is also important to avoid spicy foods to some extent that can cause irritation in the anus.
  • Bowel movements: after bowel movements it is recommended to clean the anal area with plenty of water or soft materials. It is best to do it by giving gentle touches, without rubbing so as not to irritate the area.
  • Physical activity: in addition, it is essential to lead an active lifestyle, practicing physical exercise frequently. It is the best way to strengthen the immune system to fight infections.
  • Sexual relations: when practicing sexual relations of any kind, it is essential to use adequate protection.
  • Signs: and, finally, in the event of any type of symptom, such as pain in the anus area or the expulsion of pus during bowel movements, it is important to see a doctor as soon as possible.


In short, the fistula is an abnormal connection that occurs between two structures of the body. Anal fistulas are relatively common in adults, with a higher prevalence among women. It is important to pay special attention to the symptoms and, in the event of any type of abnormal sign, see a doctor.

Website | + posts

Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of ​​Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.

Leave a Reply

Your email address will not be published.