Oesophageal reflux. Coloured X-rays showing a range of different views of the chest and upper abdomen of a 10-month-old infant with oesophageal reflux. The cardia, the region where the contents of the oesophagus empties into the stomach (across bottom), is open rather than closed as it should be. A contrast medium (white) shows the outline of the stomach and the oesophagus. Gastroesophageal reflux is where the contents of the stomach (including stomach acid) rise upwards into the oesophagus.