Home Health Anal Fistula: Causes, Symptoms and Treatment

Anal Fistula: Causes, Symptoms and Treatment

Anal Fistula: What are the Common Causes?
Anal Fistula: What are the Common Causes?

An anal fistula is a typical tunnel that forms because of an infection between the skin that covers the anus entrance and the anal canal’s inner lining. It is also called fistula-in-Ano.

Usually, an anal fistula appears with symptoms such as painful bowel motions, fever, fatigue, itchiness, redness, putrid discharge from a second hole close to your anus, swelling near your fistula’s opening, etc.

Common Causes

There are numerous underlying causes of an anal fistula. So if you experience any of the above symptoms, then it could be due to one of the several causes mentioned below.

Formation of an Anal Abscess 

Anal glands produce a fluid known as mucus in the anal canal. On occasion, anal glands may become blocked, which promotes the development of bacteria and infections. As a result, an abscess (a collection of pus that is infected) develops and eventually pierces the skin close to your anus. This resultant channel is an anal fistula.

Inflammatory Causes

Crohn’s Disease

In this chronic inflammatory bowel disease, the lining of the digestive tract becomes inflamed. Any part of the digestive tract can suffer from inflammation. When it occurs in the large intestine near the anus, it can cause an anal fistula.


It is inflammation or infection of the tiny pouches that develop in and protrude from the surface of the large intestine. It can result in an anal fistula.

Hidradenitis Suppurativa

The sweat glands in this chronic skin ailment frequently become infected and recover by scarring. When this happens in the anal region, it may cause the skin in your anal area to become infected, either significantly or superficially, and can result in the development of an anal fistula.

Sexually Transmitted Infections (STIs)

AIDS, short for Acquired Immunodeficiency Syndrome, is caused by HIV, an abbreviation of Human Immunodeficiency Virus. It is a viral infection that targets and impairs the body’s immune system. Anal abscesses and anal fistulas can develop as a result of the increased sensitivity to these infections.

Additionally, syphilis and chlamydia are some sexually transmitted infections that may raise your risk of developing an anal fistula.


A bacterial infection causes tuberculosis that affects the lungs, although it can happen anywhere in the body. It can occasionally affect your rectum, resulting in the formation of an anal abscess that tears through the surface and results in an anal fistula.

Complicated Deliveries

Difficult baby deliveries with third or fourth-degree rips can predispose you to develop an anal fistula.

Also, when episiotomy – a cut in the perineum, the tissue that lies between the vaginal entrance and the anus – occurs during childbirth, it can cause an anal fistula to develop later in life.

Anorectal Cancer

Anorectal cancer is a causal factor of an anal fistula. In this cancer, aberrant cell growth and tumour development occur in the rectum or the distal part of the colon, where faeces get collected before excretion. It can cause an anal fistula to develop.

Radiation Therapy

A cancer treatment known as radiation therapy employs high-energy beams to eradicate cancerous cells. It may harm your blood vessels that maintain the rectum’s lining and cause persistent radiation proctitis (inflammation of the lining of the rectum). It can also cause pain and constrict the skin around your anus and thus lead to the development of an anal abscess (a common causal factor of an anal fistula).

Rectal Ulcers

A painful sore that develops inside the rectum is called a rectal ulcer. These ulcers can penetrate the thickness of the gut wall and create a tunnel to drain the pus from the infected area, causing an anal abscess. Thus, the development of ulcers can lead to an anal fistula.

Trauma to the Rectal Area

Injuries in the rectal region can result in trauma. It can act as a causal factor for the development of an anal fistula.

Surgical Complications

Previous surgery around the area surrounding your anus can result in an anal abscess and the formation of an anal fistula. Also, an unsuccessful anal fistula treatment can cause a recurrence of anal fistulas.

Other Causes

An anal fistula can develop due to several other causes, such as tumours, abnormal patterns of growth, and congenital health issues.

Symptoms of an anal fistula

An anal fistula is a small tunnel that forms between the skin and the muscle around the anus. The tunnel can be short or long, and it may have several branches. Anal fistulas usually occur when there is an infection in the anal glands, which are located just inside the anus. The infection causes abscesses (pus-filled areas) to form. If the abscesses burst, they can leave a hole (fistula) in the tissue.

Anal fistulas often cause pain, itching, and drainage of pus or blood from the anus. They can also make it difficult to control bowel movements. If you have an anal fistula, you may notice that your bowel movements are very watery or that you leak stool after having a bowel movement. You may also have pain during bowel movements or when sitting for long periods of time.

If you think you might have an anal fistula, see your doctor as soon as possible so that he or she can diagnose and treat the problem.

Treatment for an anal fistula

An anal fistula is a small tunnel that forms between the skin and the muscle around the anus. The tunnel allows the infection to drain from an abscess (a pus-filled pocket) that has developed near the anal canal.

Most anal fistulas develop as a result of an infection in the glands around the anus. The infection causes an abscess, which is a pus-filled pocket, to form. The abscess eventually bursts, and the drainage creates a tunnel between the skin and muscle around the anus.

Treatment for an anal fistula typically involves surgery to close off the fistula and allow it to heal. In some cases, a seton (a piece of surgical thread or tape) may be placed in the fistula to help it heal from the inside out. Other treatments include antibiotics, sitz baths, and pain medication.


If you feel you are suffering from an anal fistula, you can consult the healthcare practitioners at Max healthcare group. These hospitals have a skilled team of doctors, specialists, and staff and possess state-of-the-art testing facilities and an outstanding success rate.

To confirm your diagnosis of anal fistula and understand everything from its symptoms and causal factors to possible treatments on a one-on-one basis, you can visit the doctors there.