['Although the 2007 AUA (American Urological Association) guidelines established it as first line therapy for ureteral stones less than 10 mm, widespread adoption of medical expulsive therapy has been low. We determined the current penetrance of medical expulsive therapy guideline recommendations and\xa0the efficacy of medical expulsive therapy in reducing the requirement for urological procedures after emergency department visits for ureteral stones.', 'In a retrospective analysis of patients seen in the emergency department we included 2,105 emergency department visits associated with an ICD-9 diagnosis of urolithiasis in which computerized tomography abdomen/pelvis scan was performed. Outcomes were reviewed for spontaneous passage or required urological procedure.', 'Ureteral stones were found in 48.8% of patients, including 50.0% in whom medical expulsive therapy was prescribed. There was no significant difference between patients who did and did not receive medical expulsive therapy. Within 12 weeks of the initial emergency department visit there was no difference in the rate of urological procedures performed in those who received medical expulsive therapy or in the rate of return to the emergency department. Patients treated with medical expulsive therapy experienced a shorter time to spontaneous expulsion (7.1 vs 12.8 days, p = 0.048).'] Is medical Expulsive Therapy Underused for the Management of Renal Colic in the Emergency Setting?