A hospital uses an esophagogastroduodenoscopy test to examine and treat problems in the upper gastrointestinal tract, explains John Hopkins Medicine. The procedure entails passing an endoscope through the mouth and throat to the duodenum.
Some problems that require the test include low blood count, nausea, swallowing problems, regurgitation and heartburn, according to MedlinePlus. In some cases, a hospital may order an EGD test if a patient has Crohn's disease or liver cirrhosis or during a medical follow-up. The patient must avoid eating for six to 12 hours before the procedure. A physician takes between five and 20 minutes to complete the test.