"Gastroesophageal" refers to the stomach and esophagus. Your LES opens to allow food into your stomach during normal digestion. As soon as it closes, food and acidic stomach juices are prevented from flowing back into your esophagus. If the LES is weak or relaxes when it shouldn't, gastroesophageal reflux occurs. As a result, stomach contents flow up into the esophagus. There are more than 60 million Americans who suffer from heartburn at least once a month, and more than 15 million who suffer from it every day, including many pregnant women. Researchers have found that GERD in infants and children is more common than doctors thought. It can cause recurrent vomiting. Other symptoms include coughing and difficulty breathing. LES weakness may lead to gastroesophageal reflux when you have a hiatal hernia, according to some doctors. Diaphragmatic hiatus occurs when the upper part of the stomach moves up into the chest through a small opening in the diaphragm. An abdominal diaphragm separates the chest from the abdomen. There is evidence that the opening in the diaphragm supports the lower part of the esophagus. There are many people who do not experience heartburn or reflux after having a hiatal hernia. However, a hiatal hernia may make it easier for stomach contents to reflux into the esophagus. When you cough, vomit, strain, or exert yourself suddenly, you can cause a hiatal hernia. A small one is common in people over 50 who are otherwise healthy. Although hiatal hernias are usually associated with middle age, they can affect anyone.