Abstract
Because YAG laser irradiation onto advanced carcinoma of the alimentary tract has a possibility to evolve carcinomatous growth, YAG laser treatment onto advanced carcinoma should be avoided except for the purpose to releasing the luminal stenosis and hemostasis. But the rectal carcinoma, considered as the type of Borrmann-I, has indicating to YAG laser treatment according to our experience. Bleeding neccesitated blood transfusion was occasionally encounterd after laser treatment. Also, abdominal distension due to assist gas jet was encounterd in gastric stomal carcinoma. The ultrasonic endoscopy is effective to differentiate from early to advanced carcinoma.