It's Not Cyclic Vomiting Syndrome Until Dietl's is Ruled Out: A Case for Point of Care Renal Ultrasound.

We present two cases of pediatric patients with episodic abdominal pain and vomiting who were previously diagnosed with cyclic vomiting syndrome. In both cases, pediatric gastroenterology evaluations had occurred with negative diagnostic testing having been performed. Both patients also presented to their primary pediatrician and the ED multiple times with each encounter resulting in treatment of symptoms and discharge. Each patient eventually presented to the ED when an EP was present who performed a renal POCUS. In each patient, the POCUS revealed severe unilateral hydronephrosis. Subsequent workup confirmed the diagnosis of Dietl's crisis as the etiology of symptoms. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In pediatric patients, EPs should be wary of the diagnosis of cyclic vomiting syndrome until ureteral obstruction has been ruled out. A bedside POCUS can rapidly establish this diagnosis and potentially preclude recurrent health care visits, unnecessary diagnostic testing, and permanent loss of renal function.