“…Because she was afebrile and did not have urinary symptoms it was unlikely that she had an infection. However, tenderness at the costovertebral angle in an afebrile patient is highly specific for obstructive uropathy [ 3 ], with her presentation of radiating pain from the left flank down to the groin raising a high suspicion for renal colic. Though classic teaching suggests ordering CT without contrast for renal colic, the choice was made to use IV contrast due to the patient's history of endometriosis, concern for possible infection, and her lack of having kidney stones.…”