Hiatus hernia. Illustration of a hiatus hernia, showing gastro-oesophageal reflux. Here, the junction between the oesophagus (at top) and the stomach (bottom) is seen. The diaphragm is the pink structure to the left and right of top of the stomach. Hiatus hernia is the condition in which the stomach protrudes through the diaphragm into the chest cavity. This results in gastro- oesophageal reflux where the contents of the stomach (acidic gastric juices) pass abnormally back up the oesophagus. Reflux may cause heart- burn, inflammation & ulceration of the oesophagus. Treatment involves avoiding large meals, stopping smoking, weight loss, & the use of antacid drugs.