This is a multi-center, randomized controlled trial of ultrasonography (ultrasound) compared to computed tomography (CT) for the initial emergency room evaluation of patients with suspected renal colic. The investigators will compare several measures of effectiveness including morbidity related to the patient's underlying disease, or complications related to delayed diagnosis, patient status regarding pain/missed days of work, and utilization of health care resources based on one of three study arms: ultrasound in the Emergency Department, ultrasound in Radiology or CT.