Barrett's esophagus has a distinct appearance when viewed during an endoscopy exam. During endoscopy, the doctor passes a flexible tube with a video camera at the tip (endoscope) down your throat and into the swallowing tube (your esophagus). The video camera detects surface abnormalities, such as acid reflux damage or the presence of a hiatal hernia or ulcers, as well as Barrett's esophagus.