This was an uncomfortable test last week.
I'll keep it simple: I drank three different drinks while being scanned and pushing my stomach against that bed as it rotated me from standing to lying down. The middle drink was the worst because it was very fizzy and immediately caused my stomach to get huge, and then I had to lie on my big stomach and pull one knee up to my stomach while I drank the last disgusting drink through a straw with my face on a pillow.
The result? They found a hiatal hernia, but my gastro doctor doesn't think it's big enough to blame for seven years of stomach pain. She ordered another test and another scan to check two other possible causes.