Inclusion Criteria:  Able to read, comprehend, and complete the consent form Aged ≥18 Clinically fit for endoscopy Referred for endoscopy via any clinical pathway  Exclusion Criteria:  Known upper GI conditions with or without ongoing endoscopic monitoring including Barrett's oesophagus, oesophageal dysplasia, gastric ulcers, duodenal polyps or any established upper GI malignancy Previous oesophagectomy, gastrectomy for malignant disease OGD performed within last 3 years of study initiation Oesophageal stricture precluding completion of diagnostic endoscopic examination Coagulopathy or anticoagulant/antiplatelet therapy for high risk conditions making non possible to discontinue the medication