Anybody ever have enterography??

I have to get one which is similar to a CT scan but the contrast drink is supposed to ?swell the intestines? so they can see it better? That is how it was explained to me. Sounds like it could be painful, so I am worried, especially since they screwed up my first one and gave me the wrong thing to drink-:) Jeez..... I am feeling good these past two weeks and really don't want to have this done but I know I should.