The diaphragm is a flat sheet of muscle tissue that separates your chest from your abdomen. Normally, all of your stomach organ is below the diaphragm. To reach your stomach, your esophagus, or "food pipe," travels down through the center of your chest and through an opening in the diaphragm. This opening is called the hiatus.
	Often as one ages, the hiatus enlarges. This allows the top portion of the stomach to slip upward into the chest cavity. That portion of the stomach which rises above the diaphragm is the hiatal hernia. The name is devrived from the fact that the stomach pushes, or herniates, through the hiatus - hence the name "hiatal hernia." This condition is quite common, but usually there are no symptoms. Activities or conditions that increase pressure within the abdomen may worsen the condition. These include persistent or heavy coughing, vomiting, straining while having a bowel movement, extreme exercises to tighten the "abs," sudden physical straining, and pregnancy.
	Here is a photo taken during a gastroscopy examination. Normally there is a "valve" between the stomach and the esophagus called the Lower Esophageal Sphincter, or LES. To prevent acid backsplash this valve should be closed all of the time - opening only when you swallow. Often with a hiatal hernia the valve becomes "pulled apart" as you see here. Then this oneway street becomes a two-way highway. The food goes down OK, but now the powerful stomach acid splashes up and damages the delicate lining of the lower esophagus. This condition is common and given the name, Gastroesophageal Reflux Disease, or GERD.

Text & Images Courtesy of Three Rivers Endoscopy Center
© Dr. Robert Fusco, Three Rivers Endoscopy Center, All Rights Reserved