Patient Resources

Ultrasound / Sonogram Prep — Fasting

Sonographer preparing an ultrasound exam at Be Well Primary Health Care Center

Ultrasound / Sonogram Prep — Fasting

Food and most liquids produce gas in the bowel, and gas blocks the ultrasound beam. Fasting is what makes a clear abdominal image possible. These instructions apply if your appointment is for an abdominal sonogram, abdominal with spectral Doppler, abdominal aorta, duplex scan of the aorta, AAA, renal, renal arteries Doppler, or renal and bladder study.

Plan for about 20 to 30 minutes in the room. If you eat beforehand, the appointment will be rescheduled.

How to prepare

  • Do not eat anything for at least 8 hours before your appointment.
  • Water only — no other liquids, including coffee, juice, or soda.
  • Do not chew gum.
  • Do not smoke — cigarettes, e-cigarettes, and vapes all count.

Medications

Check with your doctor before skipping any dose. You are welcome to bring your medication with you and take it immediately after the examination.

If your order is for a renal and bladder sonogram, follow the full bladder instructions as well — water is permitted during the fast, and it is what fills the bladder.

Download the Fasting instructions (PDF)

Not sure which prep applies to your appointment? Call Flatbush (718) 253-9355 or Bedford-Stuyvesant (347) 915-1411.