Acid Reflux (GERD) and the Esophagus
Anyone who eats a lot of acidic foods can have mild and temporary heartburn. This is especially true when lifting, bending over, or lying down after eating a large meal high in fatty, acidic foods. Persistent GERD, however, may be due to various conditions, including biological or structural problems.
Malfunction of the Lower Esophageal Sphincter (LES) Muscles
The band of muscle tissue called the LES is responsible for closing and opening the lower end of the esophagus, and is essential for maintaining a pressure barrier against contents from the stomach. For it to function properly, there needs to be interaction between smooth muscles and various hormones. If it weakens and loses tone, the LES cannot close completely after food empties into the stomach. Acid from the stomach backs up into the esophagus. Dietary substances, drugs, and nervous system factors can weaken the LES and impair its function.
Impaired Stomach Function
Patients with GERD have abnormal nerve or muscle function in the stomach. These abnormalities prevent the stomach muscles from contracting normally, which causes delays in stomach emptying, increasing the risk for acid back-up.
Abnormalities in the Esophagus
Some studies suggest that most people with atypical GERD symptoms (such as hoarseness, chronic cough, or the feeling of having a lump in the throat) may have specific abnormalities in the esophagus.
Motility Abnormalities. Problems in spontaneous muscle action (peristalsis) in the esophagus commonly occur in GERD, although it is not clear whether such problems cause the condition, or are the result of long-term GERD.
Adult-Ringed Esophagus. People with this condition have many rings on the esophagus and persistent trouble swallowing (including getting food stuck in the esophagus). Adult-ringed esophagus occurs mostly in men.
The hiatus is a small hole in the diaphragm through which the esophagus passes into the stomach. It normally fits very snugly, but it may weaken and enlarge. When this happens, part of the stomach muscles may protrude into it, producing a condition called hiatal hernia. It is very common, occurring in more than half of people over 60 years old, and is rarely serious. It was once believed that most cases of persistent heartburn were caused by a hiatal hernia. Hiatal hernia may impair LES muscle function. Studies have failed to confirm that it is a common cause of GERD, although its presence may increase GERD symptoms in patients who have both conditions.A hiatal hernia occurs when part of the stomach protrudes up into the chest through the sheet of muscle called the diaphragm. This may result from a weakening of the surrounding tissues and may be aggravated by obesity or smoking.
About 30 - 40% of reflux may be hereditary. An inherited risk exists in many cases of GERD, possibly because of inherited muscular or structural problems in the stomach or esophagus. Genetic factors may play an especially strong role in susceptibility to Barrett's esophagus, a precancerous condition caused by very severe GERD.
Other Conditions Associated with GERD
Crohn's disease is a chronic ailment that causes inflammation and injury in the small intestine, colon, and other parts of the gastrointestinal tract, sometimes including the esophagus. Other disorders that may contribute to GERD include diabetes, any gastrointestinal disorder (including peptic ulcers), lymphomas, and other types of cancer.
Click the icon to see an image of inflammatory bowel disease.
Eradication of Helicobacter Pylori
Helicobacter pylori, also called H. pylori, is a bacterium sometimes found in the mucus membranes of the stomach. It is now known to be a major cause of peptic ulcers. Antibiotics that eradicate H. pylori are an accepted treatment for curing ulcers. Of some concern, however, are studies indicating that H. pylori may actually protect against GERD by reducing stomach acid. Curing ulcers by eliminating the bacteria might trigger GERD in some people. Studies are mixed, however, on whether patients with cured H. pylori infections are at higher risk for GERD. By reducing acid production in the stomach, H. pylori may also help prevent a type of esophageal cancer called esophageal adenocarcinoma.
Still, the bacteria should be eradicated in infected patients with existing GERD who are taking acid suppressing medications. There is some evidence that the combination of H. pylori and chronic acid suppression in these patients can lead to atrophic gastritis, a precancerous condition in the stomach.
Drugs that Increase the Risk for GERD
NSAIDs. Nonsteroidal anti-inflammatory drugs (NSAIDs), common causes of peptic ulcers, may also cause GERD or increase its severity in people who already have it. There are dozens of NSAIDs, including over-the-counter aspirin, ibuprofen (Motrin, Advil, Nuprin), and naproxen (Aleve), as well as prescription anti-inflammatory medicines. People with GERD who take the occasional aspirin or other NSAID will not necessarily experience adverse effects, especially if they have no risk factors or evidence of ulcers. Acetaminophen (Tylenol), which is NOT an NSAID, is a good alternative for those who want to relieve mild pain without increasing GERD risk. Tylenol does not relieve inflammation, however.
Other Drugs. Many other drugs can cause GERD, including:
- Calcium channel blockers (used to treat high blood pressure and angina)
- Anticholinergics (used to treat urinary tract disorders, allergies, and glaucoma)
- Beta adrenergic agonists (used to treat asthma and obstructive lung diseases)
- Dopamine agonists (used in Parkinson's disease)
- Bisphosphonates (used to treat osteoporosis)
- Iron pills
Click the icon to see an image of peristalsis.