Endoscopic submucosal dissection (ESD) is widely usedin Japan as a minimally invasive treatment for earlygastric cancer. The application of ESD has expanded tothe esophagus and colorectum. The indication criteriafor endoscopic resection (ER) are established for eachorgan in Japan. Additional treatment, including surgery with lymph node dissection, is recommended when pathological examinations of resected specimens donot meet the criteria. Repeat ER for locally recurrent gastrointestinal tumors may be difficult because of submucosal fibrosis, and surgical resection is required inthese cases. However, ESD enables complete resectionin 82%-100% of locally recurrent tumors. Transanal endoscopic microsurgery (TEM) is a well-developed sur-gical procedure for the local excision of rectal tumors.ESD may be superior to TEM alone for superficial rectaltumors. Perforation is a major complication of ESD,and it is traditionally treated using salvage laparotomy.However, immediate endoscopic closure followed byadequate intensive treatment may avoid the need forsurgical treatment for perforations that occur during ESD. A second primary tumor in the remnant stomach after gastrectomy or a tumor in the reconstructedorgan after esophageal resection has traditionally required surgical treatment because of the technical difficulty of ER. However, ESD enables complete resectionin 74%-92% of these lesions. Trials of a combination ofESD and laparoscopic surgery for the resection of gastric submucosal tumors or the performance of sentinellymph node biopsy after ESD have been reported, butthe latter procedure requires a careful evaluation of itsclinical feasibility. The application of ESD has expanded tothe esophagus and colorectum. The indication criteria for endoscopic resection (ER) are established for eachorgan in Japan. Additional treatment, including surgery with lymph node dissection, is recommended when pathological examinations of resected specimens donot meet the criteria. Repeat ER for locally recurrent gastrointestinal tumors may be difficult because of submucosal fibrosis, and surgical resection is required inthese cases. However, ESD enables complete resectionin 82% - 100% of locally recurrent tumors. Transanal endoscopic microsurgery (TEM) is a well-developed sur-gical procedure for the local excision of rectal tumors. ESD may be superior to TEM alone for superficial rectaltumors. Perforation is a major complication of ESD, and it is traditionally treated using salvage laparotomy. However, immediate endoscopic closure f A second primary tumor in the remnant stomach after gastrectomy or a tumor in the reconstructedorgan after esophageal resection has traditionally required surgical treatment because of the technical difficulty of ER. However, Trials of a combination of ESD and laparoscopic surgery for the resection of gastric submucosal tumors or the performance of sentinellymph node biopsy after ESD have been reported, but the latter procedure requires a careful evaluation of itsclinical feasibility.