Bring a book! Or something to do lol. You just get to eat some eggs or oatmeal with a radioactive tracer in it (you cannot taste it at all) and then periodically the techs take you to a room where you lay down and get they essentially take x-rays of your digestive system. A 4 hour protocol test is the standard and recommended but I'm finding a lot of hospitals are only doing an 2 hr protocol which I just don't think is long enough to see all the food go through. I don't know what you're main symptomss are but mine are vomiting and nausea, if you throw up your food, the test is canceled and you have to do it again another day. I've had this done maybe 3 times now. Hope that helps

Mine was a breeze! I did it twice! It's boring though. Definitely listen to ALL the prep instructions that they give you (some people have different needs) and bring something with you to do.

It might be weird if you're claustrophobic to have the thing hanging over your for hours but other than that it's just keeping yourself entertained and calm. It was helpful to me to learn afterward that this isn't a definitive yes-or-no diagnostic test mainly because disordered stomach emptying is not a very consistent thing. I have pretty severe gastroparesis but my stomach emptying scans have technically read normal if you don't look at the fact that it didn't move at all for the first 3 hours and then all dumped at once. So don't feel as discouraged as I did 😅