No special preparation is needed before prostate ultrasound. The man is covered with a sheet during the intervention. He usually is lying on his left side, with his knees folded up to his thorax. We put a protective cover and lubricant on the ultrasound probe before inserting it into the rectum. The man may feel some pressure or have a feeling of fullness in the rectum when the transducer is in place. The transducer emits high frequency sound waves to the prostate. A computer analyses the echoes generated by the sound waves and produces images of the prostate on the screen. The image reveals the size of the prostate and any abnormalities.