A method for the treatment of Barrett's Esophagus of a patient having endothelial esophageal complications. The treatment comprises connecting a wavelength specific light source to an elongated light guide having a distal end, the light guide arranged within a lumen of a steerable endoscope, guiding the endoscope into the esophagus of the patient, energyzing the light source, and manipulating the distal end of the light source onto a target on the endothelial complications inside of the patient's esophagus for the selective thermolysis of the target in the esophagus, thereby reverting the red secretory esophageal lining to a normal lining.