Is a fistula an illness? Understanding This Complex Medical Condition

September 27, 2025 •

4 min read

An estimated one-third of people with an anal abscess will develop a fistula. While not an illness in itself, a fistula is a serious medical condition that is often the direct result of an underlying disease, infection, or injury, requiring prompt attention.

Quick Summary

A fistula is a medical condition defined as an abnormal tunnel connecting two body parts, rather than an illness itself, though it is usually caused by an underlying infection or disease. The resulting symptoms and potential complications mean it can cause significant ill health and requires medical treatment.

Key Points

Not a primary illness: A fistula is an abnormal passageway or tunnel, not an illness in itself.
Caused by underlying disease: It is almost always a result of another medical problem, such as an infection, Crohn's disease, or injury.
Leads to severe illness if untreated: Left alone, a fistula can cause serious complications like recurring infections and sepsis, which can be fatal.
Multiple types exist: Fistulas are classified by their location (e.g., anal, gastrointestinal, vaginal) and can be congenital or acquired.
Treatment is necessary: Fistulas rarely heal spontaneously and typically require medical intervention, most often surgery, to close the tract.
Impacts quality of life: The persistent symptoms can cause significant physical and emotional distress, heavily impacting daily life.
Surgical creation is possible: Some fistulas are deliberately created by doctors for treatment purposes, such as an arteriovenous fistula for dialysis.

What Exactly is a Fistula?

A fistula is a tunnel or passageway that forms abnormally between two areas of the body that are not usually connected. These tunnels can connect two organs, two vessels, or an internal organ to the skin's surface. The etymology comes from the Latin word for “pipe,” which accurately describes the tube-like structure. While some fistulas are purposefully created for medical treatments, such as for dialysis, the vast majority are pathological and cause significant health problems.

Is a Fistula Considered an Illness?

The question "Is a fistula an illness?" requires a nuanced answer. The fistula itself is best described as a condition or complication rather than a primary illness. However, it is almost always the result of an underlying infection, disease, or trauma, which is the root cause of the problem.

For example, an anal fistula often results from an abscess caused by an infected anal gland. The abscess is the infection, and the fistula is the resulting tunnel that forms to drain the pus. In this case, the fistula is a complication of the initial illness. Left untreated, a fistula can lead to persistent infection, sepsis, and other life-threatening complications, causing a state of profound illness. Therefore, while not a disease by itself, its presence indicates an underlying medical issue and creates a new, serious health problem that can make a person very ill.

Common Causes of Fistulas

Fistulas can develop from a variety of causes, with the most common being:

Infection: This is the most frequent cause of anal fistulas, where a blocked and infected anal gland creates an abscess that burrows a tunnel to drain through the skin.
Inflammatory Bowel Disease (IBD): Chronic inflammation from conditions like Crohn's disease can lead to ulcers that penetrate the intestinal wall, creating fistulas. Perianal fistulas are a common complication for Crohn's patients.
Trauma or Injury: Injuries from accidents or previous surgery can sometimes lead to fistula formation. This is a common cause for arteriovenous fistulas.
Radiation Therapy: Radiation treatment for cancer in the pelvic region can weaken tissues and increase the risk of developing a fistula.
Childbirth Complications: Prolonged or difficult labor can cause injury that leads to vaginal fistulas, though this is more common in developing countries with less access to resources.
Cancer: Tumors can create abnormal connections between organs, resulting in a fistula.

Types of Fistulas by Location

Fistulas are classified based on the parts of the body they connect. Here are a few common types:

Anal Fistula: Connects the anal canal to the skin near the anus.
Enterocutaneous Fistula: Forms between the intestine and the skin.
Rectovaginal Fistula: An abnormal connection between the rectum and the vagina, a particularly distressing complication.
Arteriovenous (AV) Fistula: A direct connection between an artery and a vein. While pathological AV fistulas can occur due to injury, they are also surgically created for dialysis patients.
Tracheoesophageal Fistula (TEF): Connects the trachea (windpipe) and esophagus, often a congenital condition in infants.

Key Symptoms to Recognize

Symptoms depend on the location of the fistula but can include:

Persistent pain, swelling, and tenderness near the opening.
Discharge of pus, blood, or stool from the skin opening.
Frequent abscesses in the same area.
Fever and general malaise, especially with an active infection.
Unpleasant odor due to drainage.
Bowel changes, such as diarrhea, or passing gas or stool through the wrong opening.

Diagnosis and Treatment

Diagnosing a fistula involves a physical exam and may include imaging tests like an MRI, ultrasound, or CT scan to map the tunnel. Treatment almost always requires a medical procedure, as fistulas rarely heal on their own. Surgical options vary depending on the fistula's complexity and location and aim to seal the connection and promote healing. For cases related to IBD, medication may be used to reduce inflammation before or during surgery.

Fistula vs. Underlying Disease: A Comparison


Feature	Fistula (The Condition)	Underlying Disease (The Cause)
Nature	An abnormal tunnel or passageway.	The root pathology, like infection, IBD, or trauma.
Symptom or Cause?	A result or complication of the underlying disease.	The origin and reason for the fistula's formation.
Treatment Focus	Surgical intervention to repair or drain the tract.	Addressing the root problem (e.g., managing Crohn's or treating infection).
Resolution	Often requires medical or surgical intervention to close.	May be chronic (like IBD) or temporary (like an infection).

Potential Complications If Untreated

Ignoring a fistula can lead to serious consequences. The continuous drainage can cause skin irritation and recurrent infections. The most severe risk is sepsis, a life-threatening complication resulting from a severe infection, which can lead to organ failure and death. In some long-standing, chronic cases, there is an extremely rare risk of cancer developing in the fistula tract.

How a Fistula Impacts Health and Quality of Life

The presence of a fistula significantly impacts a person's health and quality of life. The persistent pain, discharge, and odor can cause considerable physical discomfort and psychological distress. Managing the condition, especially if it is recurrent or complex, can be debilitating, affecting social activities, work, and overall well-being. Patients with chronic conditions like Crohn's often experience a higher burden on their health-related quality of life. Successfully treating the fistula, while potentially complex, can lead to significant improvements and a return to a more normal life. For further reading on the diagnosis, types, and causes of fistulas, you can visit the Cleveland Clinic's health library.

Conclusion: Fistulas as a Serious Health Condition

In summary, while a fistula is not a primary illness in the conventional sense, it is a serious medical condition and a tell-tale sign of an underlying health problem. It can lead to significant ill health, from recurrent infections to life-threatening sepsis, and its management is crucial for the patient's well-being. Understanding a fistula as both a symptom and a condition is the first step toward seeking the appropriate medical diagnosis and treatment.

Frequently Asked Questions

A fistula will not usually heal on its own and requires medical treatment to close the abnormal passageway. Without treatment, it can lead to chronic infection, abscesses, and more severe complications.

Yes, a fistula is often a complication of a more serious underlying illness. It is commonly associated with chronic inflammatory conditions like Crohn's disease, or can sometimes be linked to infections, cancer, or trauma.

No, a fistula is not contagious. It is an internal medical condition caused by an underlying issue and cannot be passed from person to person.

Common symptoms include persistent pain and swelling, discharge of pus or blood, and frequent abscesses. The specific symptoms depend on the fistula's location in the body.

Diagnosis typically involves a physical exam by a doctor, who may also use imaging tests like an MRI, CT scan, or ultrasound to visualize the tunnel and its origin.

While not all fistulas can be prevented, managing underlying conditions like Crohn's disease and addressing infections promptly can reduce the risk. In some cases, such as with congenital fistulas, prevention is not possible.

Surgery is the most common and effective treatment for fistulas. While other less invasive options like plugs or glues exist for certain cases, antibiotics alone are not enough to cure the condition.

Yes, fistulas can recur, especially if the underlying cause is not fully addressed or in complex cases involving conditions like Crohn's disease. This is why follow-up care is essential.