What is the prep for a renal ultrasound?

The prep for a renal ultrasound is nothing to eat or drink after midnight. The exception is that you must have completed drinking approximately 32 oz. (or have a completely full bladder) of water/clear liquids by 1 hour prior to your test time. You should start drinking about 1 1/2 hours before the procedure and finish drinking by 1 hour prior. Once you have started drinking the fluids, do not use the bathroom until after your test.