Inclusion Criteria:  : histological proven primary gastric adenocarcinoma  no evidence of other distant metastasis R0 resection laparoscopic or robotic gastrectomy and reconstructed by Roux-en-Y reconstruction or the Billroth II procedure patient with appropriate conditions of activity; 0 or 1 on Eastern Cooperative Oncology Group (ECOG) scale patient who have not previously received chemotherapy or radiation treatment in the abdomen. patinet who signed the consent form;  Exclusion Criteria:  active double cancer (synchronous and metachronous double cancer within 5 disease-free years),  carcinoma in situ, open gastrectomy, reconstructed by Billroth I procedure, gastric cancer recurrence, ;a history of gastrectomy. ; a patient who has the power of abdominal surgery except laparoscopic appendectomy and gallbladder resection a patient who need co-ordination for other organs in preoperative examination (However, laparoscopic cholecystectomy is included in the selection criteria due to gallbladder polyps, and gallbladder disease). Pregnant women, lactating women a patient with mental illness (a person diagnosed with mental illness in medical records) a patient who are taking corticosteroid whole-body (including herbal medicine) a patient who has an uncontrolled history of angina or myocardial infarction within six months of the study; uncontrolled hypertension a patient who has a serious respiratory disease that requires continuous oxygen therapy;