Besides major ESD-related complications, minor adverse events after ESD are also commonly noticed. Pain is one of minor ESD-related complications. . The causes of pain associated with ESD or gastric polypectomy are thought to be associated with transmural burn or transmural air leak. How control localized pain for patients who suffered from pain after ESD is appearing as new medical interests. There are few studies about management strategy for pain after ESD. Glucocorticoids are used to reduce inflammation and tissue damage in various clinical settings including inflammatory disease, rheumatic disease, and so on. The efficacy of glucocorticoids for reducing pain after surgery has recently been investigated. Glucocorticoids are thought to locally inhibit collagen deposition and fibrosis and finally reduce scar-tissue formation. Especially systemic steroids are easy to achieve a continuous effect through stable serum concentrations. If pain was partially associated with acute inflammation, we assumed intravenous dexamethasone could be helpful to relieve pain after ESD based on previous studies. we aimed to assess the efficacy of single dose postoperative intravenous dexamethasone for pain relief after ESD.

Inclusion Criteria:

• 20 years of age or older
• pathologically diagnosed gastric adenoma or cancer that was eligible for ESD
• patients who gave written informed consent from patients or responsible family members.

Exclusion Criteria:

• patients who take pain killer within 48 hours or regularly at enrollment
• confirmed any other disease which can induce epigastric pain such as peptic ulcer disease and gastroesophageal reflux disease
• multiple gastric lesions for ESD
• history of gastric surgery at enrollment
• severe underlying disease including infection, cardiopulmonary disease, and diabetes.