<prompt> A child with recurrent urinary tract infections is most likely to show:Posterior urethral valvesVesicoureteric refluxNeurogenic bladderRenal and ureteric calculi  <response>: Reflux is the most common cause of pyelonephritis and is found in 30 to 50 of children presenting with urinary tract infection. In primary reflux, the child on average, between 2 and 3 years of age usually presents with symptoms of pyelonephritis or cystitis. Ref:Kligman, Behrman, Jenson, Stanton 2008, Chapter 539, Vesicoureteral Reflux, In the book, Nelsons Textbook of Pediatrics, Volume 2, 18th Edition, New Delhi, Page 2229 