Anne Marie Colbin says something similar, that too much water dilutes the digestive enzymes and they don't work as well. I can see a logic, although I have no clue if it's true. I drink after a meal, usually, at least for the water that's directly linked to a meal.

Other suggestions--keep a big (plastic for safety) cup in the bathroom, and drink it down every time you brush your teeth. That can be 16 oz at each end of the day, which means you're starting with a load of water and going to bed with another that can do its "clean-up" work overnight. Might have to adjust so you can sleep through the night, but I have to admit, a full bladder sure helps get me out of bed in the morning!