Examination of how to start eating after endoscopic submucosal dissection

Interventions: Check for free air by CT scan for patients after ESD
Primary outcome(s): Presence or absence of free air on CT after ESD. Pain scores on NRS the next day after treatment, values of inflammatory response in blood sampling, vital signs, etc. will be examined, and the difference in contingency and length of hospitalization between the group eating from normal diet and the group eating from liquid diet will be examined.
Study Design: Single arm Non-randomized