Amin Afrasiabi, MDPediatric Urology
Pediatric urology

Vesicoureteral Reflux (VUR) in Children

A concise evidence-based overview of reflux, urinary tract infection, renal injury risk, and bladder and bowel function, and what remains uncertain.

Educational overview. This page does not provide medical advice for an individual child.

Clinical overview

Vesicoureteral reflux (VUR) is the retrograde passage of urine from the bladder into the ureter and, in some children, up to the kidney. It is commonly identified during evaluation after a urinary tract infection (UTI) or of hydronephrosis.

VUR, recurrent UTI, and renal scarring are related but distinct. Reflux can be present without infection or scarring, and febrile UTI also occurs in children without reflux. Management is risk-stratified. Options range from observation to antibiotic prophylaxis and endoscopic or surgical correction, and the benefits and trade-offs of each differ across clinical settings.

What clinicians follow

Infection history
Whether infections were febrile, how often they recur, and whether they were confirmed.
Kidney ultrasound
Kidney size, parenchymal appearance, and dilation, followed over time.
VCUG and reflux grade
Voiding cystourethrography shows whether reflux is present, its grade, and bladder anatomy. Whether repeat VCUGs change management, and whether ultrasound can replace VCUG, are questions discussed in the Academy.
Renal scarring and function
Renal imaging for parenchymal scarring or reduced function, when indicated.
Bladder and bowel function
Voiding pattern, continence, and constipation.
Change over time
Whether reflux persists or resolves, and whether infections or kidney findings change.

VUR grade, and why grade alone is not enough

Reflux is graded on VCUG according to how far urine refluxes and how dilated the ureter and collecting system become. Grade describes anatomy at the time of the study.

Grade alone is not the whole risk model. It does not by itself determine the risk of febrile infection, renal scarring, or whether reflux will persist. Grade is considered together with infection history, bladder and bowel function, the appearance and function of the kidneys, and the child’s overall course.

Febrile UTI and renal injury risk

In children with VUR the clinical concern is risk to the kidneys. Febrile UTI, including pyelonephritis, is a pathway to acquired renal scarring, so infection history carries weight alongside reflux itself. Renal abnormalities associated with VUR may also be congenital, so scarring or reduced function in a child with reflux does not always reflect prior infection.

Because febrile UTI also occurs in children without reflux, a febrile infection does not by itself show that reflux is the cause. This question is discussed in the Academy (“The Child With Febrile Urinary Tract Infection but No Reflux”).

Bladder and bowel dysfunction

Bladder and bowel dysfunction, including constipation and abnormal voiding patterns, is assessed in children with VUR, particularly those with recurrent UTI. It may contribute to infection and can influence how reflux is managed. Addressing it is part of overall management; this page does not describe specific treatment.

When intervention may be considered

Intervention may be considered when the overall clinical picture suggests meaningful risk to the kidneys. Factors considered include:

  • recurrent or breakthrough febrile UTI
  • reflux grade and persistence over time
  • renal scarring or reduced ipsilateral function
  • bilaterality and associated urinary-tract anomalies
  • bladder and bowel dysfunction
  • age, clinical course and family preferences

Options include continued observation, antibiotic prophylaxis, and endoscopic or surgical correction. Management is individualized: the choice among them depends on the child’s risk profile, clinical course, and family preferences, and is made by the treating team together with the family. No single threshold is proposed here.

What remains uncertain

  • which children with VUR will develop renal injury
  • how much reflux grade adds to other risk factors
  • whether repeat VCUG changes management
  • how to minimize repeat invasive imaging while still identifying clinically important persistent reflux
  • distinguishing reflux-related from non-reflux febrile UTI
  • which children derive sufficient net benefit from prophylaxis or reflux correction to justify treatment
  • how to combine risk factors into an individualized assessment

Pediatric Urology Academy

The Pediatric Urology Academy includes a dedicated season on vesicoureteral reflux (Season 2, 7 episodes). Topics include:

  • Deflux, twenty years later
  • whether every child with high-grade VUR needs surgery
  • repeat VCUGs
  • febrile UTI without reflux
  • whether ultrasound can replace VCUG
  • precision medicine in VUR
  • dogmas about VUR that are no longer true