First, be sure to give your doctor a complete list of all the medicines you are taking and any allergies you have to drugs or other substances. Your doctor will also want to know if you have heart, lung, or other medical conditions that may need special attention before, during, or after upper GI endoscopy. You will be given instructions in advance that will outline what you should and should not do in preparation for the upper GI endoscopy. Be sure to read and follow these instructions.