<prompt> For hiatus hernia, investigation of choice isBarium meal follow throughBarium meal upper GIBarium meal upper GI in Trendelenberg positionBarium meal double contrast  <response>: Barium swallow and meal examination give the best appreciation of gastro-oesophageal anatomy. The patient is in the Trendelenburg position to demonstrate barium in the fundus.Bailey and Love 26th edition Pg: 1015 