What causes foul odor in urine after vasectomy and inguinal hernia repair?

Foul-Smelling Urine After Vasectomy and Inguinal Hernia Repair

Foul-smelling urine following vasectomy and inguinal hernia repair most likely indicates a urinary tract infection, particularly if a urinary catheter was used during the procedure or if the surgery occurred more than 72 hours ago.

Primary Differential Diagnosis

The foul odor in urine suggests bacterial colonization or infection. The key considerations are:

• Catheter-associated urinary tract infection: If a urinary catheter was placed during either procedure, this is the most common cause of postoperative UTI, with duration of catheterization being the most important risk factor 1
• Postoperative urinary retention with secondary infection: Urinary retention occurs in 22.2% of patients after endoscopic hernia repair and can lead to bacterial overgrowth 2
• Timing matters critically: Fever and urinary symptoms within the first 72 hours postoperatively are usually non-infectious, but after 96 hours, infection becomes the likely cause 1

When to Obtain Urine Studies

Do NOT routinely obtain urinalysis or culture in the first 72 hours after surgery if foul-smelling urine is the only symptom 1. However, you should obtain urine microscopy, Gram stain, and culture if:

• The patient has had an indwelling bladder catheter for ≥72 hours 1
• The patient is at high risk (recent urologic surgery, which applies to vasectomy) 1
• Clinical evaluation suggests symptomatic UTI (dysuria, frequency, urgency, fever >96 hours postoperatively) 1
• The patient has systemic signs of infection 1

Specimen Collection Technique

If urine collection is indicated:

• Collect from the sampling port of the catheter, NOT from the drainage bag, to avoid contamination 1
• Practice rigorous antisepsis during collection to prevent contamination by colonizing bacteria 1
• Transport to laboratory within 1 hour or refrigerate if delayed 1

Non-Infectious Causes to Consider

While infection is most likely with foul odor, consider:

• Hematoma or wound complications: Wound infections occur in 1-2% of vasectomies and inguinal hernia repairs 3, 4
• Vas deferens injury: Occurs in 1-8% of hernia repairs, particularly with high ligation of the hernia sac, though this would not directly cause foul urine 5, 6
• Dehydration or concentrated urine: Can produce strong odor without infection

Management Algorithm

1. Assess timing: If <72 hours postoperative and no catheter was used, observation is appropriate unless other symptoms develop 1

2. Check for catheter: If catheter present ≥72 hours, obtain urine studies immediately 1

3. Evaluate for retention: Assess post-void residual if patient reports difficulty voiding, as retention is common after hernia repair and increases infection risk 2

4. If >96 hours postoperative with foul urine: Obtain urinalysis and culture, as infection is likely 1

5. Treatment: If symptomatic UTI confirmed, initiate broad-spectrum antibiotics then adjust based on culture results 3

Critical Pitfalls to Avoid

• Do not waste resources evaluating early postoperative symptoms (<72 hours) in the absence of high-risk features 1
• Do not ignore urinary retention, which occurs in over 20% of hernia repairs and is associated with narcotic use and IV fluid administration 2
• Do not assume wound infection without inspecting the surgical sites—both the scrotal incision from vasectomy and the inguinal incision from hernia repair should be examined 1