Abstract
First we reported to use of a YAG laser in treating bleeding gastric ulcers, stess ulcers, gastric polyps and early gastric cancer. Eight cases of polyps in the colon and 2 cased of early cancer of the colon were treated with a YAG laser and achived satisfactory clinical results. we think these results rationalize a wider use of laser for lesions of the distal colon. Experimental studies were made on light microscopy and scanning electron microscopy of prepared specimen of canine esophagus, stomach, duodenum and colon after laser irradiation. The high risk of perforation was noted in the esophagus and duodenum. The colon and stomach followed respectively. Laser treatment more for lesions in the colon rather than the stomach seems to be mandatory for prudential management. The espohageal mucosa is white which consists of squamous cells, and is different from the other viscera, and it is responsible for the least mucosal alteration.
