need to lose 5 pounds fast!

i have my pre-op appt tomorrow morning at 10 am. that gives me 20 hours to lose some pounds. the reason for the rush is that i learned 2 weeks ago i needed to lose about 10% of my body weight. i had put on 10 lbs since my consult then i learned i had to drop some pounds and i have gotten off most of the 10 pounds but that just puts me back at my consult weight, i need to be under that weight or the surgeon may push out my surgery date. anyone know how i can drop some pounds in 20 hours? i know it wont be healthy but i have to do it just for a very short time. please help!