Barrett's Esophagus: Diagnosis Make an Appointment Refer a Patient Ask a Question Reviewed by Luette S. Morton, MD (October 01, 2012) An upper endoscopy or esophagogastroscoduodenoscopy (EGD) is performed to diagnose Barrett’s Esophagus. The EGD allows the doctor to look inside the esophagus, stomach and small intestine. Your doctor will use a small flexible tube, starting at your mouth, to see inside your esophagus. A biopsy may also be done during the EGD. During a biopsy a small amount of the tissue is taken from the lining of the esophagus. The tissue can be studied closely to help determine if the cells where the esophagus and stomach meet show dysplasia. If dysplasia is seen this is identified as low grade, high grade or cancerous. Barrett's Esophagus: Symptoms Barrett's Esophagus: Treatment Clinical Trials For more than 100 years, National Jewish Health has been committed to finding new treatments and cures for diseases. Search our clinical trials.