A case is described of a 4 year-old girl who presented with chronic episodic abdominal pain with vomiting. Physical examination was unremarkable aside from hypertension. Point-of-care renal ultrasound showed hydronephrosis, leading to a diagnosis of ureteropelvic junction obstruction presenting with Dietl crisis (episodic abdominal pain secondary to urinary tract obstruction). The clinical utility of point-of-care renal ultrasound in the evaluation of abdominal pain and ultrasound findings of ureteropelvic junction obstruction are highlighted.