Hernia Hiatus is a hernia where part of the stomach protrudes into the chest through the esophageal hiatus in the diaphragm. It is often caused by weakening of the diaphragm muscle and esophageal opening, and increased abdominal pressure from obesity, pregnancy, ascites, or heavy lifting. There are two types: sliding hernia where the LES slides through the diaphragm, and rolling hernia where the stomach rolls into a pocket beside the esophagus. Symptoms can include heartburn, pain, bleeding, or strangulation of tissue.