A hiatus hernia occurs when part of one of the organs in the tummy protrudes through the diaphragm. Most commonly this is a part of the stomach; however, it may be other organs, such as the pancreas, spleen or the upper gut (small intestine).
This is a companion discussion topic for the original article at https://patient.info/digestive-health/acid-reflux-and-oesophagitis/hiatus-hernia