A urinary catheter is readily removed and replaced with a second urinary catheter without introducing foreign matter or contaminants into the bladder. The first urinary catheter includes an extra lumen that houses a sheath therein to seal an opening or third hole at or near the tip of the catheter so that fluids do not enter the extra lumen. After the sheath seal is broken and the sheath is extracted from the catheter, a guidewire is threaded through the extra lumen and into the patient's bladder. The first urinary catheter is withdrawn from the patient, leaving the guidewire in the patient. A second urinary catheter is inserted into the patient over the guidewire, with the guidewire present in the urine lumen of the second urinary catheter. The guidewire then is extracted from the patient.