A catheter is inserted into the bladder through the urethra and a small balloon is inflated to hold it in place. Warmed liquid, containing contrast media (dye), is allowed to run into the bladder. This liquid outlines the walls of the bladder so they can be visualised on x-rays. The catheter is removed when the bladder is full. Several x-rays are taken during the examination and the patient empties their bladder at the end of the procedure.
