I'm Getting A Camera Test Soon (one Of Those Ones

I'm getting a camera test soon (one of those ones that go down your throat) to check for what's up with my stomach problem! I'm basically extremely nervous because I've heard so many stories about how it's horrible .. I also have a phobia of throwing up (weird I know).. What I'm asking is, is it possible to ask for extra sedation? Do they do that for really nervous people?