Mucosal folding in upper urinary pathways following ureterolithiasis.

Mucosal folds in the ureter or renal pelvis were demonstrated in 2 children and 27 adults with urolithiasis. It appeared from the sequence of events observed in these cases that the folds occurred in a redundant mucosa following an episode of mural stretching. Urinalysis, including bacterial culture in the majority of cases, showed infection in only 3 of the adults.