?????Liquids?????
Ok, below is a diagram of your new insides. See how the pouch is shaped? And you don't have a pyloric valve anymore to stop things from just passing right through you stomach. That's why dense proteins keep you full longer but liquids and "slider" foods (yogurt, cottage cheese, soups) will pass through quickly.
So it's true. But why you aren't peeing more I can't say. Are you getting your 64oz in a day yet? I did pee a lot more in the beginning but once your body is fully hydrated you will slow down. Sounds backwards but it's the way it goes. You can Google that and it will confirm.
If you feel you are not peeing as much as you should you should talk to your surgeon's office or you PCP. This surgery is hard on your liver and your kidneys because of all the toxins your body is working through right now.
HTH.