Rapid Resolution of Hydronephrosis after Spontaneous Passage of Kidney Stone

Obstructing kidney stones can present with sudden onset of pain with varying degree of hydronephrosis. The timing of resolution of hydronephrosis after relief of obstruction has not been clearly demonstrated but can take days or even weeks for complete resolution. Long-standing hydronephrosis is associated with obstructive nephropathy and renal failure. We present a case of a patient with renal colic due to presumed obstructing stone with immediate complete resolution of hydronephrosis after presumed passage of a stone.