I remember when I was 6-7 going to dinner with another family and the other boy asked "When do you drink?" I said what do you mean.. He said you do drink before or after the meal. Their family had a policy of not letting him drink during the meals.
I think drinking water is fine. But most ppl don't drink water they drink soda, milk shakes, alcohol, Frappuccinos, etc. If you are are having digestion problems it is not from the water, it is from the food or drinks.
Another problem with todays foods is that they are so processed so all of the water is removed, so by not drinking water the food is actually harder to digest