Fistula: Types, Symptoms, Causes, and Treatment Options
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
A fistula is an abnormal passageway connecting two internal organs or an organ to the skin, with common types including anal, vaginal and arteriovenous. [1] Symptoms may include pain, swelling or leaking of urine, pus or stool. [1] Causes range from Crohn's disease to surgery or trauma. [1] Some minor fistulas respond to medication, but most require surgical repair.
What the research says
Treatment choice matters for complex anal fistulas. A network meta-analysis of 16 randomized trials found a higher failure rate than with an endorectal advancement flap for fistula plugs (OR 3.6; 95% CI 1.1–11.5) and fibrin glue (OR 7.5; 95% CI 2.2–25), while cutting seton carried a higher risk of incontinence (OR 8.6; 95% CI 1–72.5) (Sierra Fernández et al., Updates Surg, 2025 [2]).
Evidence for repairing vesicovaginal fistulas is still limited. A systematic review of 46 studies found no difference in successful repair between vaginal and abdominal routes, and concluded that high-quality evidence to guide repair is lacking (Thompson et al., Obstet Gynecol, 2024 [3]).
Outcomes differ widely by fistula type. In a review of 163 children with acquired rectourethral or rectovaginal fistulas (26 articles), closure was achieved in 50.3% overall: 98.4% for rectourethral fistulas but only 20% for rectovaginal fistulas, which were often linked to HIV infection or inflammatory bowel disease (Huang et al., Front Pediatr, 2021 [4]).
What is a Fistula?
A fistula is a connection between two parts of the body that do not normally connect. [1] It often takes the form of a tunnel or passageway, allowing bodily substances—such as blood, pus, or waste—to travel to areas where they should not be. These connections can form entirely within the body between two organs or lead from an internal organ to the outer surface of the skin. [1]
While most fistulas are abnormal and require medical attention, healthcare providers occasionally create them intentionally for therapeutic purposes. [1] For example, a dialysis fistula is a surgically created connection between an artery and a vein designed to support long-term kidney treatment. [1]
Feature | Description |
Structure | A tunnel or passageway connecting two distinct areas [1] |
Nature | Typically abnormal, but can be surgically created (e.g., for dialysis) [1] |
Location | Between organs, blood vessels, or an organ and the skin [1] |
Primary Risk | Disruption of normal bodily processes and risk of infection |
Common Types of Fistulas
Fistulas are categorized based on the specific body parts they connect. The following are the most frequently diagnosed types:
Anal and Digestive Fistulas
An anal fistula is an abnormal passageway leading from the inside of the anus to the skin surface. [1] These often develop following a perianal abscess or as a complication of inflammatory conditions like Crohn’s disease. [1] In more severe cases, an aortoenteric fistula can form between the aorta and the small intestine, leading to life-threatening gastrointestinal bleeding. [1]
Vaginal and Obstetric Fistulas
Vaginal fistulas are openings in the vaginal wall that connect to nearby organs, such as the bladder (vesicovaginal) or the rectum (rectovaginal). [1] An obstetric fistula specifically refers to a connection that forms as a complication of prolonged or obstructed labor during childbirth. [1]
Vascular and Specialized Fistulas
An arteriovenous (AV) fistula is a direct connection between an artery and a vein. [1] While these can occur accidentally due to injury, they are often created by surgeons to provide a durable access point for hemodialysis. [1] Other specialized types include perilymphatic fistulas in the ear and tracheoesophageal fistulas connecting the windpipe and esophagus. [1]
Symptoms and Warning Signs
The symptoms of a fistula depend heavily on its location and the type of substances passing through the abnormal tunnel.
Fistula Type | Common Symptoms |
Anal | Pain, swelling, and drainage of pus, blood, or stool near the anus [1] |
Vaginal | Leaking of urine, stool, or gas from the vagina; painful intercourse [1] |
Arteriovenous | Bulging veins, swelling, skin color changes, or warmth in the area [1] |
Aortoenteric | Severe abdominal cramping, bloody vomit, or black/bloody stools [1] |
Perilymphatic | Dizziness, hearing loss, ear fullness, and balance issues [1] |
Causes and Risk Factors
Fistulas generally develop when tissue is damaged by prolonged inflammation, infection, or physical trauma. [1]
Infection and Inflammation: Chronic conditions such as Crohn’s disease or diverticulitis can cause deep inflammation that eventually tunnels through organ walls.
Trauma and Injury: Accidental injuries or trauma to a specific area of the body can force a connection between adjacent structures. [1]
Surgical Complications: Some fistulas form as an unintended side effect of a surgical procedure or radiation therapy. [1]
Congenital Factors: Certain types, like tracheoesophageal fistulas, may be present at birth due to changes during fetal development. [1]
Diagnosis and Testing
Healthcare providers use a combination of physical examinations and advanced imaging to locate and assess a fistula. [1]
Physical Examination
The provider will review the patient’s symptoms and perform a targeted exam. For fistulas that connect to the skin, the opening may be visible. For internal fistulas, the provider may feel for abnormalities or check for unusual drainage. [1]
Imaging and Diagnostic Tests
Radiology: CT scans, MRIs, and X-rays help visualize the path of the fistula and its impact on surrounding tissues. [1]
Endoscopy: Scopes such as colonoscopies, cystoscopies, or bronchoscopies allow providers to see inside the digestive tract, bladder, or airways. [1]
Angiography: Used specifically for vascular fistulas to check for disrupted blood flow. [1]
Laboratory Tests: Blood and urine tests can identify signs of active infection or inflammation. [1]
Management and Treatment
The goal of treatment is to close the abnormal connection, manage symptoms, and prevent the fistula from returning.
Medication
In cases where a fistula is caused by an infection, antibiotics are prescribed. [1] For fistulas related to inflammatory conditions like Crohn’s disease, immunomodulators may be used to reduce inflammation and encourage the tissue to heal. [1]
Surgical Repair
Most fistulas require surgery to be fully resolved. The complexity of the procedure depends on the fistula’s size and location.
Simple Repairs: Closing the tunnel and removing damaged tissue.
Complex Procedures: Some cases may require multiple surgeries or the use of specialized grafts to ensure the connection remains closed.
Outlook and Prevention
While most fistulas are successfully treated, they can sometimes recur, especially if the underlying cause—such as a chronic inflammatory disease—is not well-managed. Mental health support is often recommended for those dealing with chronic or recurring fistulas, as the condition can be physically and emotionally taxing. [1]
Prevention: While most fistulas cannot be prevented because they result from unpredictable injuries or medical conditions, obstetric fistulas are largely preventable. [1] Access to skilled medical care during labor and the availability of emergency C-sections are critical in reducing the incidence of childbirth-related fistulas. [1]
If you notice unusual drainage, persistent pain, or symptoms that suggest an abnormal connection in your body, contact a healthcare provider immediately. Early diagnosis is key to preventing serious complications and ensuring a smoother recovery.
This article provides general information and is not a substitute for professional medical advice. Always consult a qualified healthcare provider about persistent drainage, pain, or swelling.
Frequently Asked Questions
What exactly is a fistula?
A fistula is an abnormal, tunnel-like connection between two body parts that should not be joined, such as two organs or an organ and the skin. [1]
Can a fistula heal on its own?
While some very small fistulas may heal with medication and rest, the majority require surgical intervention to close the passageway permanently.
Is an anal fistula dangerous?
If left untreated, an anal fistula can lead to recurring infections, abscesses, and systemic illness. It requires medical evaluation to prevent complications.
Why do surgeons create fistulas for dialysis?
A surgically created arteriovenous (AV) fistula connects an artery to a vein, creating a larger, stronger blood vessel that can withstand frequent needle insertions for dialysis. [1]
What causes a vaginal fistula?
Vaginal fistulas are often caused by complications during childbirth (obstetric fistula), surgery, radiation therapy, or inflammatory bowel diseases.
How do I know if I have a fistula?
Common signs include unusual drainage (pus, stool, or urine) from a small opening, persistent pain, swelling, and recurring infections in the same area.
What is an aortoenteric fistula?
An aortoenteric fistula is a rare but life-threatening connection between the body’s main artery (aorta) and the small intestine, causing severe internal bleeding. [1]
How is a fistula diagnosed?
Diagnosis typically involves a physical exam followed by imaging tests like a CT scan, MRI, or an endoscopy to visualize the internal tunnel. [1]
Can fistulas be prevented?
Most fistulas caused by injury or disease cannot be prevented, but obstetric fistulas can be avoided through proper medical monitoring during labor. [1]
What should I expect after fistula surgery?
Recovery varies by the type of surgery but usually involves managing the wound, preventing infection, and follow-up appointments to ensure the connection has closed.
Content reviewed and produced following the Rinnit editorial framework. Last updated: October 8, 2026.
References
Cleveland Clinic. Fistula. Cleveland Clinic Health Library. Medically reviewed; last updated February 26, 2024. https://my.clevelandclinic.org/health/diseases/fistula
Sierra Fernández I, Balciscueta Coltell Z, Uribe Quintana N. Systematic review and network meta-analysis of cryptoglandular complex anal fistula treatment: evaluation of surgical strategies. Updates Surg. 2025;77(4):1067-1078. PMID 40442569. doi:10.1007/s13304-025-02270-6
Thompson JC, Halder GE, Jeppson PC, et al. Repair of vesicovaginal fistulae: a systematic review. Obstet Gynecol. 2024;143(2):229-241. PMID 38033311. doi:10.1097/AOG.0000000000005468
Huang X, Tan SS, Chen Y, et al. Acquired rectourethral and rectovaginal fistulas in children: a systematic review. Front Pediatr. 2021;9:657251. PMID 34026691. doi:10.3389/fped.2021.657251
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