What are the indications for an Upper Endoscopy or EGD (Esophagogastroduodenoscopy)?

Anemia, abdominal pain, bloating, belching, loss of appetite, weight loss, heartburn, acid reflux, difficult or painful swallowing, nausea, vomiting, or an abnormal CT Scan, MRI, or UGI X-Ray, and other symptoms that may be related to gastrointestinal disturbances.