<Tr> <Th> MeSH </Th> <Td> D014718 </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> Vesicoureteral reflux (VUR), also known as vesicoureteric reflux, is a condition in which urine flows retrograde, or backward, from the bladder into the ureters / kidneys . Urine normally travels in one direction (forward, or anterograde) from the kidneys to the bladder via the ureters, with a 1 - way valve at the vesicoureteral (ureteral - bladder) junction preventing backflow . The valve is formed by oblique tunneling of the distal ureter through the wall of the bladder, creating a short length of ureter (1--2 cm) that can be compressed as the bladder fills . Reflux occurs if the ureter enters the bladder without sufficient tunneling, i.e., too "end - on". </P> <P> Most children with vesicoureteral reflux are asymptomatic . Vesicoureteral reflux may be diagnosed as a result of further evaluation of dilation of the kidney or ureters draining urine from the kidney while in utero as well as when a sibling has VUR (though routine testing in either circumstance is controversial). Reflux also increases risk of acute bladder and kidney infections, so testing for reflux may be performed after a child has one or more infections . </P>

Which disorder involves the retrograde passage of infected urine