 An esophageal gastrodiodinoscopy, OGD, is a visual examination of the lining of your esophagus, stomach and diodenum. Pre-procedure, a 6-8 hour fast is advised. Inform the doctor about any underlying medical conditions and if you are on blood thinners. During the procedure, local anesthesia is sprayed on your throat to make it numb. You may also be given a sedative by injection. A mouth guard is placed to facilitate endoscope passage through the mouth. Later, the doctor passes the endoscope through your mouth and throat and you will be asked to swallow. The endoscope will not interfere with your breathing nor cause any pain. If necessary, small tissue samples may be taken painlessly for pathologic examination. After the procedure, do not attend to eat or drink until your swallowing reflex is normal. If you have had a sedative injection, do not operate any heavy machinery. Please contact your doctor immediately if you experience any complications.