I Just Had My Gall Bladder Removed This Morning. I

I just had my gall bladder removed this morning. I have been drinking fluids - water and minimal Gatorade per discharge orders. I have had many sensations that I need to urinate, but when I try, limited to no results. It seems to be getting a little better. I am curious if this is related to pain block or anesthesia? Also, should I keep drinking fluids? I estimate inhale had about 4 glasses of water since being discharged.