I am guessing it is the same thing if he was talking about viewing the upper GI tract, not the lower part. An upper GI is a barium x-ray. The "with follow through" will take a tad longer but lets the dr. see it pass through the small bowel more. I have had many of these--doesn't hurt. The nastiest part is swallowing the thick chalky liquid but it honestly is not that bad. Then you wait . . . they will take x-rays before you start and throughout, usually every so many minutes. Bring something to read while you wait! At one point (usually at the end), the radiologist may press on your bowels with a balloon-like paddle to get a better look at the loops of bowels. IF you are tender, it might hurt a bit then.
Welcome to the Crohn's club! Upper GI's will probably become part of your regular testing over the years.
Best of luck!