Here we’ll quickly look at the cardia and how it can impact symptoms of acid reflux and GERD.

The last 5 centimeters or so of the esophagus lie under the diaphragm in the abdomen. The esophagus meets the stomach at its upper right-hand surface, not quite at the top. If the stomach was a clock face, and you were looking at it from the front, the meeting of the esophagus and the stomach (the esophageal-stomach junction) would be at 11 o’clock.

This junction is the ‘cardia’. It meets the stomach at an angle, so that food slides easily downwards from the esophagus into the bottom 90 per cent of the stomach. It is not unlike tipping a glass to one side when you pour a fizzy drink into it, to avoid turbulence and froth. The angle should also ensure that, if there is any reverse movement of food upwards in the stomach, it passes by the entry into the esophagus (the cardia) and ends up in the top 10 per cent of the stomach. Continuing the analogy with the clock face, that’s the 12 o’clock area, or the ‘fundus’.

The fundus, being the uppermost part of the stomach, is virtually an unexpanded balloon. It is a safety valve that gathers any gas that has been swallowed with food (that’s why we ‘burp’ babies after their feeds) or produced during digestion. It normally sits neatly under the diaphragm.