A 36-year-old patient was admitted to the emergency department with complaints of severe flank pain, nausea, vomiting, anuria, and general illness. Five months earlier, we had placed a subcutaneous pyelovesical prosthesis (Detour; Porges) of the ureter for treatment of a chronically dilated upper urinary tract in a solitary right kidney previously treated by double-J stenting. Ultrasonography of the right kidney revealed severe hydronephrosis. A percutaneous nephrostomy catheter was placed, and antegrade pyelography showed complete obstruction of the prosthesis. Urinalysis and culture demonstrated a Candida infection. A systemic antimycotic was administered, and fluid management was started. On the third day, diuresis appeared, and antegrade nephrostomography confirmed patency of the bypass.