Causes of Fistula-in-Ano:

An anal fistula is a small, painful tunnel. It develops between the inside of the anal canal and the outer skin around the anus. When patients notice pain, swelling, or unusual discharge, they often ask: “What causes fistula disease? Understanding why this happens is the most important step toward getting a permanent cure and protecting your long-term health.

At Kaizen Fistula Care, we believe that patient education is very important. Led by our expert colorectal surgeon, Dr. Samrat Jankar, our clinic focuses on finding the exact anal fistula causes for each person. By finding why the tunnel formed in the first place, we can design a precise treatment plan.

If you are experiencing discomfort, learning about fistula causes will help you make good choices. Kaizen Fistula Care offers advanced, minimally invasive treatments to help you return to a pain-free life quickly and safely. Let us look deeper into what triggers this condition and how different fistulas develop.

Fistula Causes

A fistula is an abnormal connection that links two organs or tissues that should not be connected. While they can happen in different parts of the body, the most common type is the anal fistula (fistula-in-ano).

1. The Primary Causes of Fistula in Ano

The vast majority of anal fistulas start from a simple, everyday issue inside the anal canal.

Blocked Anal Glands: Your anal canal contains small glands that secrete fluid. Sometimes, these glands become blocked with bacteria or fecal matter.
Anal Abscess Formation: Once a gland is blocked, it quickly turns into an infection. This infection creates a painful collection of pus, known as an anal abscess.
The Path of Infection: As the pus builds up, it creates intense pressure. The infection naturally forces its way through the surrounding tissue to get out. It eventually bursts through the skin around the anus.
The Leftover Tunnel: Even after the abscess drains and the swelling goes down, the path it carved out often remains open. This permanent, abnormal tract is what causes fistula in ano.

2. General Anal Fistula Causes and Risk Factors

An unhealed or poorly drained abscess is the most common reason. However, there are several other notable what causes anal fistula factors:

Inflammatory Bowel Disease (IBD): Conditions like Crohn’s disease cause chronic inflammation in the digestive tract. This inflammation can weaken the walls of the rectum and anus, leading to deep tissue ulcers that form complex fistula tracts.
Trauma or Surgery: An injury to the anal area can trigger a fistula. Deep tearing from severe constipation can also cause it. Sometimes, complications from a previous pelvic surgery accidentally damage the tissue walls.
Infections and Radiation: Specific infections like tuberculosis or HIV can cause long-term tissue inflammation and deep abscesses. Additionally, patients undergoing radiation therapy for pelvic cancers may experience tissue breakdown over time, leading to abnormal tunnel formation.

3. Other Types of Fistula Causes Around the Body

Fistulas do not only occur in the anal region. Depending on the organs involved, their underlying causes vary:

Tracheoesophageal Fistula Causes: This is an abnormal connection between the windpipe (trachea) and the gullet (esophagus). In newborns, tracheoesophageal fistula causes are almost always congenital. This means it is a birth defect. In adults, esophageal fistula causes are typically linked to throat cancers or severe chest trauma.
Causes of Vesicovaginal Fistula: This type is an abnormal tract between the urinary bladder and the vagina. It leads to continuous, uncontrollable urine leakage. Globally, the primary causes of vesicovaginal fistula are prolonged, obstructed labor during childbirth. In developed regions, it is more commonly caused by pelvic surgeries like a hysterectomy.
Rectovaginal Fistula Causes: This is a tunnel connecting the rectum to the vagina. It allows gas or stool to escape through the vagina. Common rectovaginal fistula causes include deep tears during childbirth, severe Crohn’s disease, or complications from pelvic cancer treatments.

Critical Patient Concerns: Can a Fistula Cause Cancer or Death?

When dealing with a long-term infection, many patients worry about the ultimate risks.

Q. Does Fistula Cause Death?

A standard anal fistula itself is a localized issue. It is not a direct threat to life. However, if you ignore the symptoms, the deep infection can spread. The trapped pus can enter your bloodstream. This severe infection is called sepsis. So, while a simple tract does not directly end life, an ignored abscess can cause death if it leads to untreated sepsis. Timely treatment at Kaizen Fistula Care completely eliminates this risk.

Q. Can a fistula cause cancer?

Many patients ask: fistula can cause cancer? A standard fistula is completely benign (non-cancerous). However, if an anal fistula is ignored for many years—typically 10 to 20 years—the constant inflammation inside the tract can rarely lead to cancer. While this is highly uncommon, it highlights why you should never leave a chronic, draining fistula opening untreated for years.