Bottles = potential flying missiles to be launched at the stage, and therefore are generally not allowed. However, some venues are more strict and check more carefully than others. To avoid excessive checking, see my feminine hygiene tip. However, in Chicago, a staff member of the venue walked along the inside part of the outside rail of the ellipse, and handed out mini-bottles of water to people during the show. They obviously cared about our hydration levels.
Around the time of the last tour, I was commuting 2 1/2 hours a day to school, and would often get held up at school unexpectedly when my advisor would have me complete some menial task at the last minute, before I could go home, and so I always kept an emergency granola bar in my bag for these occasions. I forgot that I even had it in there, and neglected to do my feminine hygiene trick, and security at one of the venues found it, and made me throw it out. Fuckers.
Sorry to hear of all this, lol! Most venues I work, sealed bottles of water are perfectly fine! Up to a gallon bag of food is also fine at most concert venues in Boston. The general concern on water is it being mixed w/ alcohol, hence the factory sealed, not tampered with requirement. The missile thing is only a concern of a few bands that request we take the caps so nothing full hits the stage.
Love the feminine hygiene tip! Alot of idiots I work with dont check to the bottom of bags. I do, but I also have common sense and in the order of priorities, you having water or a granola bar is just not that bothersome to me or any other guard w/ common sense. I would say to you upon seeing your bag "hey, I did not see that granola bar"" or something like that! One of the things that gets me about security searches(front door is my speciality in Boston) is the guards that go crazy about stupid shit. When do I care? When 2 15 yr olds each have 6 beer cans. When some 30 yr old whack job has a laser pen, when someone has a knife or mace. When someone is so drunk they can not walk. You get the idea.
except that SUCKS!!! You also sometimes risk escalating things to the level where bad security throws you out too. Ugh.
We're crazy. 
