During radiofrequency ablation treatment for Barrett's esophagus, your doctor uses an endoscope to insert a thin tube, or catheter, down your esophagus. The catheter has a balloon at the end, with electrodes on the outer surface. The balloon is inflated so the electrodes are touching the abnormal tissue in the lining of the esophagus. The electrodes deliver enough energy to destroy thin layers of the diseased or abnormal tissue.