Large hiatal hernia  
This is a large hiatal hernia. A hiatal hernia is a portion of the stomach that has been pulled up into the chest above the breathing muscle, or the diaphragm. Normally, the stomach is entirely in the abdomen, though when pulled above that muscle, which separates the chest from the abdomen, a bit of the stomach is in the chest. In this case, the hiatal hernia appears to be entirely normal, in that the tissue looks completely normal. This is an extremely common condition, and may make it more likely that one who has it develops heartburn.