Why can't i pass gas or go to the bathroom? i drunk a lot of water today and nothing, what's going on with my body.

It depends on what you were doing.: Your physical activity as well as the environment largely dictates how much fluid you need. Here in Arizona where the temperature in the summertime is often over 110°F you need substantially more fluid than you would in a place like Seattle. So if you are working outside or doing manual labor outside you're going to lose substantially more fluids. In order to urinate in a larger quantity you're going to need to drink more fluid. It just depends on the environment and your activity