Most common predisposing factor for chronic pyelonephritis is:
Chronic pyelonephritis is so often associated with vesicoureteric reflux that some feel that it is better named "Reflux nephropathy". It is impoant cause of renal damage and death from end - stage renal failure.
Diabetes mellitus
Renal stone
Posterior urethral valve
Vesicoureteric reflux
Kidney and ureter