I recommend you eat light the night before and make sure you take Dulcox after surgery. I did not and boy was I sorry!
At my hospital I didn't have to worry about taking Dulcolax. They would not discharge you from the hospital until you could prove that your digestive system was functioning. Unfortunately for me that meant I was handed the dreaded Dulcolax suppository before I could be set free. Once I got home drinking plenty of fluids and taking stool softeners keep things in working order.
As far as eating the night before all I can say is follow their protocol. When I had my sternum wires taken out I was NPO (nothing by mouth) after midnight. My surgery was scheduled for 9AM and I arrived at the hospital at 7AM. My surgeon had TWO emergency surgeries come up and I finally got wheeled into surgery at 4PM. Nothing to eat or drink for 16 HOURS! Enjoy your meal the night before. The reason they give you a cut off time is because they know how long it takes the body to digest food to the point that it's no longer in your stomach. And trust me on this one...they will get whatever you ate the night before to start moving after surgery. They have their ways.