Fig. 1

At 24 days of life, voiding cystourethrogram is showing absence of bladder (B) and urethral abnormalities, but right-sided vesicoureteral reflux with moderate dilatation of the ureter (U), renal pelvis (R) and calyces and blunting of fornices as well as accidental finding of persistent distended stomach (S) with undulating contours known as Caterpillar sign, virtually pathognomonic for hypertrophic pyloric stenosis