This prospective multicenter randomized controlled trial will compare stent-related symptoms after placement of a ComfiJ ureteral stent versus a conventional double-J ureteral stent in adult patients undergoing unilateral ureteroscopy or retrograde intrarenal surgery for urinary stones when short-term postoperative ureteral stenting is clinically indicated. Eligible patients will be randomized intraoperatively after the operating surgeon confirms the need for postoperative stenting. The primary outcome will be the Ureteral Stent Symptom Questionnaire urinary symptoms domain score on postoperative day 14 before planned stent removal.