Your doctor will probably tell you to refrain from eating or drinking for about eight hours prior to the exam. This is because these actions increase the amount of abdominal gas and could alter blood flow in the upper abdominal organs or cause the gallbladder to contract, preventing an adequate ultrasound examination.
Abdominal scanning is usually done with you lying flat on an examination table. Garments are elevated or pulled down to expose the lower abdomen from the navel to the pubic bone. Abdominal scanning may or may not require a full bladder. A full bladder provides a "window" through which the pelvic organs can be seen. Your doctor may, therefore, ask you to drink a large quantity of water and/or refrain from urinating just prior to the examination. Preparations for vaginal scanning are similar to those for a routine manual pelvic examination. You will be asked to empty your bladder prior to the exam and to disrobe from the waist down. You will need to assume a position similar to the one used for a Pap smear. A thick cushion might be necessary to elevate your buttocks.
No preparation is necessary.
Enema to empty the rectum. This may be performed at home prior to arrival in the Ultrasound Department.
For most Doppler ultrasound exams, no preparation is necessary. Your doctor could ask you to refrain from eating on the morning of your exam if the ultrasound scan involves your upper abdomen.