Pain may be referred to the epigastrium from damage to structures derived from the foregut.

During breathing, the diaphragm contracts and flattens, displacing the viscera and producing an outward movement of the upper abdominal wall (epigastric region).

[1] Therefore, the epigastric region is not a muscle nor is it an organ, but it is a zone of activity where the actions of the rectus abdominis and the diaphragm produce an outward bulging of the upper abdominal wall.

The epigastrium is the part of the abdomen where abdominal thrusts (the Heimlich manoeuvre) are able to produce a rapid and forceful exhalation of breath.

[4] This is primarily from the foregut, with structures including the stomach, parts of the duodenum, and the biliary tract.