Urachal fistula - Causes, Treatment & When to See a Doctor

What is Urachal Fistula?

A urachal fistula is an abnormal channel that connects the bladder (or the urachus) to the skin surface of the lower abdomen. During fetal development the urachus—a thin tube that carries urine from the bladder to the umbilical cord—is supposed to close and become a fibrous band called the median umbilical ligament. When this closure is incomplete, the residual tract may remain open (patent) and form a fistula. The fistula allows urine or mucus to leak from the bladder to the outside of the body, most often through the umbilicus.

Urachial abnormalities are relatively rare, occurring in less than 0.02 % of the population, but they are clinically important because they can lead to recurrent infections, irritative urinary symptoms, and, in rare cases, malignant transformation.

Sources: Mayo Clinic; CDC

Common Causes

Most urachal fistulas are congenital, meaning they arise from an embryologic failure to close the urachus. However, several conditions can either reveal a previously silent fistula or cause an acquired fistula. The most frequent causes include:

• Congenital patent urachus – failure of the urachal lumen to obliterate before birth.
• Urachal cyst infection – an infected cyst can erode into the skin, creating a fistulous tract.
• Trauma or surgery – abdominal or pelvic surgery (e.g., laparoscopic hernia repair, bladder surgery) may inadvertently damage the urachus.
• Urinary tract infection (UTI) – severe infection can extend to the urachal remnant.
• Neoplasms – urachal adenocarcinoma or other malignancies can invade and open a fistula.
• Radiation therapy – pelvic radiation may weaken tissue and precipitate fistula formation.
• Chronic catheterization – long‑term indwelling catheters increase infection risk, potentially involving the urachus.
• Diverticulitis of the urachus – rare, but inflammation can cause a tract to the skin.
• Inflammatory bowel disease (IBD) – severe inflammation near the midline can involve the urachus.
• Granulomatous disease (e.g., tuberculosis) – can produce an ulcerating sinus that mimics a fistula.

Associated Symptoms

Because a urachal fistula creates a direct path between the bladder and the skin, many patients notice characteristic signs:

• Clear or yellowish discharge from the umbilicus – often described as “wet” or “dripping” especially after urination.
• Foul odor – a sign of infection.
• Pain or tenderness around the belly button – may increase with bladder filling.
• Recurrent urinary tract infections – due to bacterial migration through the fistula.
• Lower abdominal swelling or a palpable mass – represents an urachal cyst or abscess.
• Fever, chills, or malaise – systemic response to infection.
• Difficulty urinating or a sense of incomplete emptying – irritation of the bladder neck.
• Blood or mucus in the discharge – may indicate inflammation or, rarely, malignancy.

When to See a Doctor

Any persistent discharge from the umbilicus, especially when accompanied by pain, fever, or urinary symptoms, warrants medical evaluation. Prompt assessment is essential to prevent complications such as:

• Severe infection or abscess formation.
• Fistula enlargement causing continuous urine leakage.
• Development of urachal carcinoma (≈1 % of urachal anomalies become malignant).

Seek care promptly if you notice any of the following:

• Discharge that does not stop after a few days.
• Redness, swelling, or warmth around the belly button.
• Fever ≥ 38 °C (100.4 °F) or chills.
• Pain that worsens when you urinate.
• Blood in the discharge or urine.

Diagnosis

Diagnosing a urachal fistula involves a combination of history, physical examination, and imaging studies. The typical diagnostic pathway is:

1. Clinical Examination

• Inspection of the umbilicus for discharge, ulceration, or granulation tissue.
• Palpation of the midline to feel for a cord‑like structure or a cystic mass.
• Assessment for signs of infection (erythema, warmth, tenderness).

2. Laboratory Tests

• Urinalysis and urine culture – to identify organisms causing concurrent UTI.
• Complete blood count (CBC) – looking for leukocytosis indicating infection.
• Inflammatory markers (CRP, ESR) – may be elevated in acute inflammation.

3. Imaging

• Ultrasound – first‑line, non‑invasive; can detect a fluid‑filled tract, cyst, or abscess.
• Contrast‑enhanced CT scan of the abdomen and pelvis – provides detailed anatomy, shows the fistulous tract, and rules out malignancy.
• MRI – useful for soft‑tissue delineation, especially in children or pregnant patients.
• Fistulography – injection of contrast into the umbilical opening under fluoroscopy to map the tract.

4. Pathology (if surgery is performed)

• Biopsy of the fistulous tract or any excised cyst to exclude cancer.

Reference: CDC; NIH National Library of Medicine

Treatment Options

Management depends on the patient’s age, the presence of infection, and whether there is an underlying malignancy. Treatment goals are to eliminate the fistula, treat infection, and prevent recurrence.

Conservative / Medical Management

• Antibiotics – Empiric broad‑spectrum agents (e.g., amoxicillin‑clavulanate or a fluoroquinolone) are started after cultures are drawn; tailored once sensitivities return.
• Local wound care – Gentle cleaning with saline, application of non‑adherent dressings, and keeping the area dry.
• Drainage of abscess – Small collections may be aspirated under ultrasound guidance.
• Urinary catheterization – Temporary bladder drainage can reduce pressure on the fistula while infection is treated.

Conservative measures alone are rarely curative; most patients ultimately need surgery.

Surgical Management

1. Complete excision (partial cystectomy with urachal remnant removal) – The gold‑standard treatment. The surgeon removes the entire urachal tract from the bladder dome to the umbilicus, often including a cuff of bladder wall.
2. Laparoscopic or robotic‑assisted approach – Minimally invasive, associated with less pain and quicker recovery.
3. Open midline incision – Used when a large infected mass or suspicion of cancer exists.
4. Umbilicoplasty – Cosmetic reconstruction of the belly button after removal of the tract.
5. Adjunctive procedures – If a coexisting bladder stone or diverticulum is present, it may be addressed simultaneously.

Post‑operative care includes antibiotics for 5–7 days, pain control, and wound monitoring. Pathology of the excised tissue is mandatory to rule out urachal adenocarcinoma.

Home Care After Treatment

• Maintain clean, dry dressings; change daily or per provider instructions.
• Stay well‑hydrated to promote urine flow and reduce infection risk.
• Watch for signs of recurrence (new discharge, pain, fever).
• Follow up with the surgeon or urologist within 2–4 weeks post‑op.

Prevention Tips

Because many urachal fistulas are congenital, they cannot be prevented. However, risk reduction for acquired fistulas and complications is possible:

• Prompt treatment of urinary tract infections – Use prescribed antibiotics and complete the full course.
• Good peritoneal hygiene in newborns – Keep the umbilical stump clean and dry; monitor for atypical discharge.
• Avoid unnecessary abdominal surgery near the midline – When surgery is required, ensure the surgeon is aware of the urachal anatomy.
• Manage chronic catheter use – Replace catheters per protocol, use aseptic technique, and consider intermittent catheterization when feasible.
• Regular follow‑up after urachal surgery – Early detection of recurrence or malignancy improves outcomes.
• Maintain a healthy weight – Obesity increases intra‑abdominal pressure, potentially stressing a residual urachal tract.

Emergency Warning Signs

Key Take‑aways

A urachal fistula is an uncommon but treatable condition that creates an abnormal connection between the bladder and the skin of the lower abdomen. While many cases are present at birth, infections, trauma, or malignancy can also cause or expose a fistula later in life. Typical symptoms include umbilical discharge, pain, and recurrent UTIs. Early evaluation with ultrasound or CT, followed by definitive surgical excision, offers the best chance for cure and prevents serious complications such as abscess formation or cancer. Patients should seek medical attention promptly for any persistent discharge, fever, or worsening pain, and they should be aware of emergency red‑flag signs that require immediate care.

References:

1. Mayo Clinic. “Urachal abnormalities.” https://www.mayoclinic.org. Accessed June 2026.
2. Centers for Disease Control and Prevention. “Urinary Tract Infections – Clinical Guidance.” https://www.cdc.gov. Accessed June 2026.
3. National Institutes of Health, National Library of Medicine. “Urachal carcinoma and other urachal lesions.” https://pubmed.ncbi.nlm.nih.gov. 2023 review.
4. Cleveland Clinic. “Urachal anomalies in children and adults.” https://my.clevelandclinic.org. Accessed June 2026.
5. World Health Organization. “Infection prevention and control guidelines.” https://www.who.int. 2022.