Rapid Resolution of Hydronephrosis after Spontaneous Passage
Patients with renal colic due to obstructing kidney stones often present with hydronephrosis on renal ultrasound or computed tomography (CT scan). Pain typically improves with resolution of obstruction by passage of stone. The timing of complete resolution of hydronephrosis after relief of obstruction is poorly understood. Resolution of hydronephrosis decreases a patient’s risk for obstructive nephropathy, renal failure, infection, and sepsis. We present a case showing moderate to severe hydronephrosis on ultrasonography in a patient presenting with acute right side pain. A CT scan was also completed within one hour of the ultrasound and revealed complete resolution of the hydronephrosis.

Case Report
The patient is a 23-year-old female with a sudden onset of colicky right side abdominal/flank pain. The pain is associated with nausea, urinary urgency and frequency. There is no history of fever, chills, vomiting, dysuria, or hematuria. She has a history of “small kidney stones”. She has no history of vaginal discharge, vaginal bleeding, ovarian cysts, and no past surgeries. All of her vitals are within normal limits. She had mild tenderness in the right lower quadrant and mild tenderness over the right costovertebral angle. Urinalysis shows 1+ blood, 7 RBCs, 2 WBCs, negative for nitrites, leukocyte esterase, and bacteria. Pertinent labs include WBC of 7.6, creatinine of 0.63, and negative serum HCG....