How should i properly prepare for a pyelogram?

Unclear: If you mean intravenous pyelogram, then there is no specific preparation but need no heavy breakfast e.g. Clear liquids like juice since I.V. Contrast could cause nausea. But if you mean a retrograde pyelogram, a contrast injected in the urethra and bladder upwards to kidneys by the urologist, then you need to be fasting after midnight to avoid vomiting and aspiration during procedure.