No special preparation is required for a routine ultrasound. Wear loose comfortable clothing to your ultrasound appointment.
For a liver or gallbladder scan, the patient is usually asked to fast (take nothing by mouth) for several hours before the test.
For a scan in early pregnancy, the woman is usually asked to drink several glasses of water and not to pass urine for a few hours before the test. A full bladder helps to improve the view of the uterus by displacing nearby loops of intestine.