There is creatine and there is creatinine clearance. You have to consume either a creatine supplement or meat, preferrably red meat. Your body metabolizes creatine to creatinine and then they measure creatinine clearance. I think I have read that 25% of people that do not consume excess creatine will fail with a negative dilute. What is your height and weight?

Gatorade, powerade, whatever.