Management A patient presenting with flank pain with or without the presence of hematuria should be evaluated for a kidney stone After a history and physical examination to evaluate for a solitary kidney or chronic kidney disease and for the presence of a fever, an ultrasound is the first-line imaging that should be obtained Initial medical management should include hydration (this should be IV until there is no chance that the child will have to undergo urgent surgical management), and pain control with narcotics and nonsteroidal anti-inflammatory medications, if there is no evidence of renal dysfunction If a stone is suspected and the ultrasound is abnormal but does not show a stone specifically, a low-radiation noncontrast CT scan can be obtained; however this is not required The patient can be treated with medical expulsion therapy alone, including pain medication and tamsulosin If the patient requires surgical decompression, there are three modalities available: percutaneous nephrostomy tube placement or retrograde placement of a ureteral stent, or extracorporeal shock wave lithotripsy (ESWL) ACUTE URINARY RETENTION CLINICAL PEARLS AND PITFALLS A seemingly benign presentation may have an underlying significant problem A perforated bladder augmentation can be life threatening, and must be diagnosed and treated on an urgent basis Urinary retention in a small child may be the only presenting sign of a rhabdomyosarcoma Background A patient with acute urinary retention is unable to empty the bladder even though it is full The cause may be bladder outlet obstruction, or may be due to lack of bladder function, as a result of a neurologic problem, or may be volitional Goals of Treatment Recognize the problem, and facilitate drainage of the bladder Clinical Recognition Determining the underlying etiology of the urinary retention is of key importance, as is determining who is at risk for complicating factors from experiencing