For hiatus hernia, investigation of choice is
Barium meal follow through
Barium meal upper GI
Barium meal upper GI in Trendelenberg position
Barium meal double contrast
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
C.V.S