Fistula: Symptoms, Types, Causes and Treatment

Fistulas are abnormal connections between two epithelial-lined surfaces, such as organs or vessels, that can severely affect a person's quality of life. They come in many forms, may arise from various underlying causes, and can manifest with diverse symptoms depending on their location and severity. Understanding fistulas is crucial for timely diagnosis and effective management. This article presents a comprehensive overview of fistula symptoms, types, causes, and current treatment options, guided by the latest clinical research and real-world data.

Symptoms of Fistula

Fistulas can present with a range of symptoms, which can be subtle or severe, and often depend on the anatomical sites involved. Recognizing these symptoms is critical for early intervention and improved outcomes.

Symptom	Description	Common Fistula Types	Source(s)
Persistent Leakage	Continuous or intermittent discharge of urine, feces, or pus from an abnormal opening	Obstetric, Anal, GI, Genitourinary	2 3 7 9 12
Pain	Localized pain, can be sharp, burning, or throbbing	Anal, Arteriovenous, GI	1 3 7
Swelling/Edema	Swelling in affected areas, sometimes with redness or heat	Arteriovenous, Anal	1 3
Itching/Pruritus	Sensation of itchiness around the opening	Anal, Cutaneous	3
Incontinence	Loss of control over urine or feces	Obstetric, Genitourinary, GI	2 9 12
Fever	Systemic sign of infection	Anal, GI, Post-surgical	3 7
Edema/Mottling	Swelling, discoloration in lower limbs	Arteriovenous	1

Table 1: Key Symptoms

Understanding Fistula Symptoms

Persistent Leakage

One of the hallmark signs of many fistulas is persistent leakage from an unnatural opening. For instance, women with obstetric fistula may experience continuous leakage of urine and/or feces from the vagina due to an abnormal connection between the bladder/rectum and the birth canal. This leakage can be socially and emotionally devastating, often leading to isolation and stigmatization, especially in resource-poor settings where medical help is scarce 2 9 12.

Pain and Discomfort

Pain is a frequent complaint, particularly with anal and arteriovenous fistulas. Anal fistulas often present with pain, especially during defecation, and may be accompanied by swelling, itching, and a sensation of anal dampness. In arteriovenous fistulas, especially those involving large vessels in the abdomen, back pain is a predominant symptom 1 3.

Swelling, Edema, and Mottling

In certain types, such as aortocaval or iliac arteriovenous fistulas, severe lower extremity edema and skin mottling can occur. This swelling may be mistaken for more common conditions like venous thrombosis, leading to diagnostic confusion 1.

Itching and Pruritus

Anal fistulas frequently cause itching and pruritus around the external opening, sometimes associated with skin irritation and moisture 3.

Incontinence

Loss of control over urine or feces is a particularly distressing symptom seen in obstetric, genitourinary, and some gastrointestinal fistulas. This symptom is not only a physical burden but also has profound psychosocial consequences 2 9 12.

General and Systemic Symptoms

Some patients, especially those with infection or inflammation, may experience fever. In certain cases, such as anal or gastrointestinal fistulas, systemic signs can indicate a serious underlying infection that requires urgent medical attention 3 7.

Types of Fistula

Fistulas are classified based on their anatomical location, complexity, and underlying cause. Each type presents unique challenges in terms of diagnosis and treatment.

Type	Description	Key Features / Subtypes	Source(s)
Anal	Abnormal tract between anal canal and skin	Superficial, Intersphincteric, Trans-sphincteric, Suprasphincteric, Extrasphincteric	4 5 6 14 16
Obstetric	Between vagina and bladder/rectum	Vesicovaginal, Rectovaginal, Ureterovaginal	2 9 12 13 15
Gastrointestinal (GI)	Abnormal connection within GI tract or to skin	Enterocutaneous, Enterovesical, Enteroenteric	7 10 18
Arteriovenous	Between artery and vein	Aortocaval, Iliac arteriovenous	1
Hidradenitis Suppurativa-related	Fistulas in skin due to chronic inflammation	Dermal, Dermoepidermal, Complex, Subcutaneous	8

Table 2: Major Fistula Types

Breakdown of Fistula Types

Anal Fistula

Anal fistulas are among the most common and well-studied. They are classified according to their relationship with the anal sphincter muscles:

• Superficial: Tract runs beneath the skin, not involving sphincters.
• Intersphincteric: Passes between internal and external sphincters.
• Trans-sphincteric: Crosses both sphincters.
• Suprasphincteric: Arches above the external sphincter.
• Extrasphincteric: Extends from rectum above the sphincters to skin 4 5 6.

Complexity increases with higher involvement of sphincter muscles, affecting treatment strategy and prognosis 14 16.

Obstetric and Genitourinary Fistula

Obstetric fistulas, often seen in resource-poor countries, typically result from prolonged obstructed labor. The main subtypes include:

• Vesicovaginal: Between bladder and vagina, leading to urinary incontinence.
• Rectovaginal: Between rectum and vagina, causing fecal incontinence.
• Ureterovaginal: Between ureter and vagina, with persistent urine leakage 2 9 12 13 15.

Iatrogenic fistulas may result from surgical errors during procedures like cesarean section or hysterectomy 13.

Gastrointestinal Fistula

GI fistulas can develop between any parts of the digestive tract or between the tract and the skin. Subtypes include:

• Enterocutaneous: Between intestine and skin.
• Enterovesical: Between intestine and bladder.
• Enteroenteric: Between two intestinal segments 7 10 18.

They may be congenital or acquired, with the latter often resulting from surgery, inflammatory diseases, or malignancy.

Arteriovenous Fistula

These occur when an artery connects directly to a vein, bypassing capillaries. Aortocaval and iliac arteriovenous fistulas are rare but serious, often presenting with back pain, edema, and high-output cardiac failure 1.

Hidradenitis Suppurativa-Related Fistula

In chronic skin diseases like hidradenitis suppurativa, fistulas can form in the skin, classified based on depth and complexity (dermal, dermoepidermal, complex, subcutaneous). Their management may require both medical and surgical interventions 8.

Causes of Fistula

Fistulas can develop due to a variety of underlying processes. Identifying the cause is crucial for effective treatment and prevention.

Cause	Mechanism / Risk Factor	Example Fistula Types	Source(s)
Obstructed Labor	Prolonged pressure, tissue necrosis	Obstetric (vesicovaginal, rectovaginal)	2 9 12
Surgery/Iatrogenic	Injury during medical procedures	Genitourinary, GI	1 13 15 18
Inflammation/Infection	Chronic inflammation, tissue damage	Anal (Crohn's disease, TB), GI	3 7 11 17
Trauma	Direct injury (e.g., gunshot wound)	Arteriovenous, GI	1 7
Malignancy	Tumor invasion/necrosis	GI, Gynecologic	10 7
Chronic Skin Disease	Recurrent abscesses, sinus tracts	Hidradenitis Suppurativa	8

Table 3: Common Causes of Fistula

Deeper Dive into Fistula Etiology

Obstetric Causes

Prolonged obstructed labor is a leading cause of fistulas in women in low-resource settings. The sustained pressure of the baby’s head against the pelvic tissues cuts off blood supply, causing tissue necrosis and subsequent fistula formation, most often between the vagina and bladder or rectum 2 9 12. Malnutrition, young maternal age, and lack of access to skilled care increase the risk.

Surgical and Iatrogenic Causes

Medical procedures, especially in emergency or complex cases, can inadvertently result in fistula formation. Cesarean sections, hysterectomies, and other gynecological or abdominal surgeries are notable culprits. Iatrogenic genitourinary fistulas are increasingly recognized and may require complex repairs 1 13 15 18.

Inflammatory and Infectious Causes

Chronic inflammatory diseases such as Crohn’s disease can lead to fistula formation, particularly in and around the anus. The process involves ongoing inflammation, epithelial damage, and abnormal healing, resulting in abnormal tracts between the bowel and other structures or the skin 3 11 17. Tuberculosis and other chronic infections can also cause fistulas.

Trauma

Physical trauma, such as penetrating injuries (gunshot wounds, accidents), can create abnormal connections between organs or vessels, leading to fistulas like aortocaval or enterocutaneous types 1 7.

Malignancy

Cancers, especially those affecting the gastrointestinal or gynecological organs, can erode into neighboring tissues, creating fistulas. These are often complex and may occur due to tumor invasion or as a complication of radiotherapy 10 7.

Chronic Skin Disease

In conditions like hidradenitis suppurativa, chronic abscesses and sinus tracts may evolve into complex fistulas, often requiring specialized management 8.

Treatment of Fistula

Treatment strategies for fistulas vary widely and are tailored to the fistula’s type, location, complexity, and underlying cause. Recent advances favor less invasive and sphincter-preserving options when possible.

Treatment Approach	Description / Technique	Application/Effectiveness	Source(s)
Surgical Repair	Direct closure, flap procedures, seton placement	Anal, Obstetric, GI, Genitourinary	12 14 15 16
Sphincter-Sparing	Ligation of tract, advancement flaps, plugs	Complex anal, recurrent fistulas	14 16
Medical Therapy	Antibiotics, anti-TNF, immunosuppressants	Crohn’s-related, initial management	11 17
Conservative/Drainage	Prolonged catheterization, endoscopic drainage	Early genitourinary, GI (post-op)	15 18
Minimally Invasive	Fibrin glue, laser, stem cell therapy	Mixed results, evolving evidence	16
Multimodal/Combined	Surgery + medical (e.g., Crohn’s)	Complex, recurrent cases	17

Table 4: Fistula Treatment Options

Current and Emerging Treatment Modalities

Surgical Repair

Surgery remains the mainstay for most fistulas. In anal and obstetric fistulas, options include fistulotomy (tract opening), excision, direct closure, or use of tissue flaps for complex cases. For vesicovaginal fistulas, transvaginal repair is most common, but abdominal or laparoscopic approaches may be employed depending on location and complexity. Surgical outcomes are generally good, especially when performed by experienced teams 12 14 15 16.

Sphincter-Preserving Techniques

For complex or high-lying anal fistulas, preserving continence is a priority. Techniques like ligation of the intersphincteric fistula tract (LIFT), advancement flaps, and bioprosthetic plugs have gained popularity. These approaches aim to eradicate the fistula while minimizing sphincter injury and incontinence risk 14 16.

Medical Management

In fistulas related to Crohn’s disease, medical therapy plays a vital role. Antibiotics help control infection, while biologic agents (e.g., anti-TNF therapies) can promote healing and reduce recurrence. Immunosuppressants may be used in combination to optimize outcomes. Surgery is reserved for cases not responding to medical management 11 17.

Conservative and Endoscopic Approaches

Some fistulas, particularly early or post-surgical genitourinary fistulas, may heal with conservative measures such as prolonged catheter drainage. Endoscopic internal drainage is now preferred over closure techniques for post-bariatric GI fistulas, especially when collections are present, as it offers higher success rates and fewer complications 15 18.

Minimally Invasive and Novel Therapies

Minimally invasive modalities like fibrin glue injection, laser therapy (FiLaC), and stem cell treatments are being explored. While some show promise, results are variable, and more research is needed to establish their role in routine practice 16.

Multidisciplinary and Combined Approaches

Complex cases, especially those associated with Crohn’s disease or malignancy, often require a team approach involving surgeons, gastroenterologists, and other specialists. Combining surgery with optimized medical therapy can enhance healing and reduce recurrence 17.

Conclusion

Fistulas are a diverse group of abnormal connections that can have profound impacts on health and quality of life. Early recognition of symptoms, accurate classification of type and cause, and individualized treatment are key to effective management.

Main Points Covered:

• Fistulas present with symptoms such as persistent leakage, pain, swelling, and incontinence, varying by type and location 1 2 3 9.
• They are classified by anatomical location and complexity. Major types include anal, obstetric/genitourinary, gastrointestinal, arteriovenous, and skin-related fistulas 4 5 6 7 8 9 10.
• Key causes include obstructed labor, surgery, chronic inflammation (e.g., Crohn’s disease), trauma, malignancy, and chronic skin diseases 1 2 3 7 8 9 11 12 13.
• Treatment is tailored to the individual, with surgical repair still central for most types, but a growing emphasis on sphincter-sparing, minimally invasive, and medical therapies, especially for complex or recurrent cases 12 14 15 16 17 18.

Early diagnosis, multidisciplinary care, and advances in treatment continue to improve outcomes for those living with fistulas. If you or someone you know experiences unexplained leakage, pain, or persistent wounds, prompt medical attention is essential for effective management and recovery.