An upper endoscopy, also called an endoscopy or EGD (esophagogastroduodenoscopy), is a minimally invasive procedure to evaluate your upper digestive tract, including the esophagus, stomach, and the first part of your small intestine, called the duodenum. The procedure is performed with an endoscope, a long, flexible tube the width of your pinky finger with a light and tiny camera at the end.