Hi Ashley --
I think PPI-LESS mentioned he had had the impedence test, and it came back negative...even though he has symptoms. It's true that reflux comes and goes depending upon a lot of factors, and certainly your chances are better with a 48-hour test to catch something than with a 24-hour one. In my case, I don't usually notice the reflux when it happens, but the Bravo study showed tons of episodes.
As far as not eating an acidic meal -- at least with the Bravo study -- you're recording your meals on a diary, so, those periods are factored in to the analysis. I would say go ahead and eat what you're accustomed to.
My most recent GI requested that I get an impedence test done, but I couldn't find anyone within 150 miles that still does the test. It has largely been replaced by the Bravo, but it does provide some unique info that the Bravo does not.
My first Bravo almost a year ago showed over 100 episodes of reflux during the 48 hours, and I was pretty uncomfortable during that time. However, the Bravo I had in October showed that I'm in the "normal" range, yet I'm still struggling with LPR symptoms following the TIF surgery in August. Your mileage may vary, but I think you can be confident that if you have a reflux problem, it will show up.
I normally eat a bland diet most of the time, anyway, and don't eat meat or spicy dishes. So, I very rarely consume any trigger foods. Don't drink soda, coffee, or tea either -- not because of the reflux, just because I never developed the habit.
Have fun traveling, and good luck with your tests!