While much is said about the symptoms of gastrointestinal reflux disease and its uncomfortable symptoms, the underlying cause of the illness, a malfunction or weakening of the lower esophageal sphincter, doesn't get as much press. Understanding the esophagus and the lower esophageal sphincter and why the lower esophageal sphincter might not be working properly is key to understanding GERD, however.
Nearly everyone who has GERD is familiar with its main symptom, burning, uncomfortable heartburn caused by the reflux of acid into the esophagus. Much of the treatment for GERD is aimed at alleviating these symptoms, with surgery being the only way to fix the cause, which, as mentioned before, is an improperly functioning lower esophageal sphincter.
The esophagus is an organ of the body which is basically a muscular tube that food passes through on its way down from the pharynx, to the stomach. The esophagus passes through the diaphragm, through a hole called the esophageal hiatus. The average esophagus is about 30 centimeters long and is divided into three parts, the cervical, thoracic and abdominal segments.
The esophagus is also known as the gullet, and derives its name from the Latin word oesophagus, which itself is a derivation from the Greek oisophagos, or "entrance for eating."
The esophagus aids in digestion by connecting the pharynx with the stomach. The esophagus contains many small muscles that use peristaltic action, to move swallowed food into the stomach. The esophagus doesn't have the same lining as the stomach, so it can easily be irritated by stomach acid that may be refluxed from the stomach.
Once food is passed down the esophagus, it works to keep food contents or acid from refluxing by means of the upper and lower esophageal sphincters, although the lower esophageal sphincter is the more significant of the two valves.
The lower esophageal sphincter is located at the cardia, or the junction of the stomach and the esophagus. There's a lot of pressure in the area of the lower esophageal sphincter, as there is a high concentration of esophageal and diaphragm muscles there. The pressure helps keep the lower esophageal sphincter closed so the contents of the stomach, undigested food and stomach acid, can't reflux back up into the esophagus.
When the lower esophageal sphincter opens in the course of normal functioning as food moves down the esophagus via contractions of the muscles of the esophagus. These contractions are begun by the process of swallowing. Once you stop swallowing, your lower esophageal sphincter will close, keeping stomach acid and food from refluxing into your esophagus and possibly back up into the windpipe. In conjunctions with the lower esophageal sphincter, the gastroesophageal flap may also close shut once your stomach is full. This flap is located near the top of the stomach, where the esophagus extends into the stomach.
The primary cause of GERD is a malfunction of the lower esophageal sphincter. When the lower esophageal sphincter is weakened or not functioning well, it allows stomach acid and food back into the esophagus. This irritates the esophagus, which doesn't have the same, tough lining that the stomach has. When the esophagus is irritated, it can result in heartburn. If the reflux and irritation of the esophagus continues over time, it can result in GERD, which has a number of uncomfortable symptoms and some possibly serious health implications.
Most of GERD treatment involves alleviating the symptoms of GERD through lifestyle modification and medication. More aggressive surgical treatments can be used to correct the weakness of the lower esophageal sphincter.
There's a method doctors can use to test the muscle strength of the lower esophageal sphincter called esophageal manometery. Doctors use this test when determining whether to order esophageal surgery.
In the test, a doctor or technician will run a thin tube into your nose, down your throat and into your esophagus. You'll then be asked to take a few sips of water. Computer sensors on the tube will gauge the pressure in your esophagus as the muscles in the esophagus contract and relax and your lower esophageal sphincter opens and closes.
Once the test is over, your doctor will evaluate the results. If the test shows that the power of your esophageal muscles has diminished, or if there's a problem with a malfunctioning lower esophageal valve. From the results of this test, your doctor will be able to determine whether surgery to repair the lower esophageal sphincter would be beneficial.