Its absurb to ban the drinking of plain water whether or not it spill on the floor etc etc....
Perhaps they should do a full check a la airport style to ensure you're not carrying, bombs and in this case waterbottles as well. Any food or waterbottles found must be bagged and sealed, and shown to the staff at the alighting station.
For those who say its alright to ban water, you should be able to tahan till you reach your destination, you don't need to take your medication on the dot, I'm sure you'll be agreeing with every word and sentiment that you've said here today when the time comes when you really need that water, or you really need to take your meds.
Inform staff or consult doctor? Perhaps I don't have the fortune to own a car, perhaps I have to get to the docs by public transport, perhaps I can't afford a cab. What do you propose then, you willing to sponsor a house call for me? You chaps are off your bloody rocks