Patient Resources

Ultrasound / Sonogram Prep — Full Bladder

Patient drinking a glass of water before a bladder ultrasound

Ultrasound / Sonogram Prep — Full Bladder

A full bladder acts as a window for the ultrasound beam. Without it, the images are not diagnostic and the study has to be repeated. These instructions apply if your appointment is for a transabdominal, pelvic, pelvic with spectral Doppler, prostate, or renal and bladder sonogram.

Plan for about 20 to 30 minutes in the room.

How to prepare

  • One hour before your exam — start drinking water. About 1 liter, roughly 8 small cups, spread over 40 minutes.
  • Stop drinking 20 minutes before the exam.
  • Do not empty your bladder until the exam is complete. Your bladder must be full for the study to be done. If it is not full, you may need to reschedule.

One more thing

If your order is for a renal and bladder sonogram, you also need to follow the fasting instructions — no food for 8 hours, water only. Water is what fills the bladder, so the two sets of instructions work together.

Download the Full Bladder instructions (PDF)

If you are unsure which prep applies to your appointment, call us: Flatbush (718) 253-9355 or Bedford-Stuyvesant (347) 915-1411.