Review Question - QID 212543

A 26-year-old man comes to the emergency room complaining of episodic back pain. He states that it started suddenly this morning. The pain is 9/10 in severity and radiates to his left groin. He endorses seeing blood in his urine earlier but denies dysuria or abnormal urethral discharge. His medical history is significant for Crohn disease, gout, and insulin-dependent diabetes. He takes insulin, allopurinol, and sulfasalazine. He is sexually active with multiple women and uses condoms inconsistently. He drinks 4 cans of beer on the weekends and denies tobacco or other recreational drug use. His temperature is 99°F (37.2°C), blood pressure is 121/73 mmHg, pulse is 89/min, and respirations are 14/min with an oxygen saturation of 94% on room air. A contrast computed tomography of the abdomen and pelvis reveals a 5-mm stone in the left ureter without evidence of hydronephrosis. Urinalysis and urine microscopy reveal hematuria and envelope-shaped crystals. Which of the following most likely contributed to the development of the patient’s symptoms?