An upper GI test is a type of X-ray that helps doctors learn how your digestive system works. It doesn't hurt, although you won't be able to eat for a few hours before you have it. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.