Ok, so I had a Barium Swallow Test yesterday.  It entails you drinking Barium while the Radiologist and Tech take x-rays of your stomach/pelvic area.  It helps the Radiologist see if there is something wrong with your "innards."  I took a peek at the monitor during parts of the test and I could see the Barium going down my esophagus, into upper GI, and then into the lower GI.  COOL!  I had this test to rule out GI problems.  I've been having a mystery pain in my pelvic/abdominal area for several months.  Me and my docs are trying to find out what is causing the pain.  I'm waiting to hear from my doc regarding the results. 

This is a fasting test, so no food or drink after midnight.  I recommend that you get a very early appointment the next day that way you won't be hungry for an entire day.  Also, you may get a little constipated or experience some bloating and/or gas!  Lastly, don't be alarmed if the day after your test you see a white poo nugget in your toilet.  The Barium turns your poo white as a Beluga Whale.  Beluga Whales are cute.  My white poo was not!  If you would like to see a picture of my poo, no just kidding, if you would like to see a picture of a Beluga Whale click on the link and imagine a small version of that swimming in your toilet bowl. 
http://en.wikipedia.org/wiki/Beluga_(whale)