This prospective randomized controlled trial evaluates the effectiveness and safety of different nasal irrigation solutions for postoperative care after endoscopic sinus surgery in patients with chronic rhinosinusitis. Patients undergoing endoscopic sinus surgery will be randomly assigned to receive nasal irrigation with normal saline, mucomyst, or diluted povidone-iodine solution for three months after surgery. Clinical outcomes, symptom scores, endoscopic findings, and potential ototoxic effects will be evaluated to compare the effectiveness and safety of these irrigation methods.