* eso-: Refers to the esophagus, the tube that carries food from your mouth to your stomach.
* phago-: Means "to eat" or "to swallow."
* gastro-: Refers to the stomach.
* duodeno-: Refers to the duodenum, the first part of the small intestine.
* -scopy: Means "to examine" or "to view."
Therefore, "esophagogastroduodenoscopy" literally means "examination of the esophagus, stomach, and duodenum."