Vesicoureteral reflux is defined as which phenomenon?

• A. Retrograde regurgitation of urine from the bladder up the ureter into the collecting system
• B. Forward flow of urine from kidney to bladder
• C. Hematuria without infection
• D. Obstruction of the ureter

Answer: (A)

Vesicoureteral reflux is the backward, retrograde flow of urine from the bladder up the ureter into the kidney’s collecting system due to imperfect closure of the vesicoureteral junction during bladder contraction. Normally this junction closes to prevent urine from flowing upward; when it doesn’t, urine can reflux toward the kidney. This backward flow increases the risk of ascending infections and renal scarring, especially in children. By contrast, forward flow from kidney to bladder is normal physiology, and hematuria without infection or ureteral obstruction describes different issues, not reflux. Diagnosis is typically via imaging during voiding to visualize the backflow.