What's the deal with water restrictions?

OK, I get why we can't drink water for thirty minutes before eating after having RNY (filling up the pouch not leaving room for our nutritious food) but I'm not sure why we can't drink anything for thirty minutes after. Are we trying to prevent a situation where the water helps force the food to slide down the intestinal tract to quickly? I'm not sure..What I am sure of is that somebody reading this has already knows the answer, so please share it with me and anyone else who has been wondering!

I'm not sure why we can't drink anything for thirty minutes after. three reasons,  1.  it will flush the food through faster, and they want you to remain full as long as possible, so that you dont want to eat more, and it gives the intestines a chance to better digest the food. 2. try it, and you will be sorry if you are anywhere near full, especially if you are newly pre-op. As many here will tell you its easy to drink 1/8th of cup too much and end up tossing your cookies in the porcelain alter. Even if you dont throw up, later you will probably wish you had. 3. Water makes lots of food expand, so that one crouton you ate, that is sitting there nice and small balloons 4 times its size when you take a drink.

Michael, Well said James! It also allows you to feel like you can eat more and that makes it hard to break the old mentality of  eating too much afterthe body is sending the I'M FULL signal(s). Joe

I asked my nutritionist the same thing. Along with the previous reasons, she said that food passes too quickly through the tract if pushed by water for our malabsorptive bowel to handle. It's hard enough for us to extract the nutrients we need. We don't need to turn up the conveyor belt speed. Think "I Love Lucy" in a chocolate factory.

--Jake

Thanks for all the great answers guys, It all makes sense to me now  I knew I could count on the collective wisdom of the locker room!