I just called the hospital and asked about why I can't have water and they said that if for some…

I just called the hospital and asked about why I can't have water and they said that if for some reason I had to go under general anesthesia, anything in my stomach could go up into my lungs. Eesh! Creepy! But they did say I could swish water around my mouth and then spit it out. That should help the feeling of being dehydrated, right?