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Digestive System

Disorders Of The Digestive System

Several disorders of the esophagus are esophagitis, esophageal spasm, and esophageal cancer. Esophagitis (heartburn) is an inflammation of the esophagus usually caused by the reflux of gastric acids into the esophagus and is treated with (alkalis) antacid. Esophageal spasm is also caused by acid reflux and is sometimes treated with nitroglycerine placed under the tongue. Esophageal cancer can be caused by smoking and is generally fatal.

Disorders of the stomach include hiatal hernia, ulcers, and gastric cancer. A hiatal hernia occurs when a portion of the stomach extends upwards into the thorax through a large opening in the diaphragm. It is a condition that commonly occurs to people over the age of 50. Stomach ulcers are sores that form in the lining of the stomach. They may vary in size from a small sore to a deep cavity, surrounded by an inflamed area, sometimes called ulcer craters. Stomach ulcers and ulcers that form in the esophagus and in the lining of the duodenum are called peptic ulcers because they need stomach acid and the enzyme pepsin to form. Duodenal ulcers are the most common type. They tend to be smaller than stomach ulcers and heal more quickly. Ulcers that form in the stomach lining are called gastric ulcers. About four million people have ulcers and 20% of those have gastric ulcers. Those people who are at most risk for ulcers are those who smoke, middle-age and older men, chronic users of alcohol, and those who take anti-inflammatory drugs, such as aspirin and ibuprofen.

Until 1993, the general belief in the medical community concerning the cause of stomach ulcers was that there were multiple factors responsible for their development. By 1993 there was mounting evidence that an S-shaped bacterium, Helicobacter pylori, could be one of the factors causing ulcers. Helicobacter pylori live in the mucous lining of the stomach near the surface cells and may go undetected for years. Researchers argued that irritation to the stomach caused by the bacteria weakened the lining, making it more susceptible to damage by acid and resulting in the formation of ulcers.

Barry Marshall, an Australian gastroenterologist, was the chief proponent of the theory that stomach ulcers are caused by H. pylori infections, rather than a multiple factor explanation, such as stress or poor diet. Although Marshall was discouraged by his colleagues from pursuing this line of research, he demonstrated his hypothesis by swallowing a mixture containing H. pylori. Marshall soon developed gastritis, which is the precursor condition to ulcers.

The treatment of ulcers has undergone a radical change with Marshall's discovery that stomach ulcers are caused by H. pylori infections. Ulcer patients today are being treated with antibiotics and antacids rather than special diets or expensive medicines. It is believed that about 80% of stomach ulcers may be caused by the bacterial infection, while about 20% may be from other causes, such as the use of anti-inflammatory medicines.



Maryon-Davis, Alan, and Steven Parker. Food and digestion. London; New York: F. Watts, 1990.

Peikin, Steven R. Gastrointestinal Health. New York: Harper-Collins, 1991.

Jordan P. Richman


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—A digestive enzyme found in saliva and the pancreas that breaks down carbohydrates to simple sugars.


—A greenish yellow liquid secreted by the liver and stored in the gall bladder that aids in the digestion of fats and oils in the body.

Gastric juice

—Digestive juice in produced by stomach wall that contains hydrochloric acid and the enzyme pepsin.


—A hormone produced by the stomach lining in response to protein in the stomach that produces increased gastric juice.

Helicobacter pylori

—Recently discovered bacteria that live in gastric acids and are believed to be a major cause of most stomach ulcers.

Lower esophageal sphincter

—A strong muscle ring between the esophagus and the stomach that keeps gastric juice, and even duodenal bile from flowing upwards out of the stomach.

Lymphatic system

—The transport system linked to the cardiovascular system that contains the immune system and also carries metabolized fat and fat soluble vitamins throughout the body.


—The digestive lining of the intestines.


—Vitamins, minerals, proteins, lipids, and carbohydrates needed by the body.


—The wavelike motion of the digestive system that moves food through the digestive system.


—Finger-like projections found in the small intestine that add to the absorptive area for the passage of digested food to the bloodstream and lymphatic system.

Additional topics

Science EncyclopediaScience & Philosophy: Dependency - The Intellectual Roots Of Dependency Thinking to Dirac equationDigestive System - Ingestion, Digestion In The Stomach, Gastric Juice, Alexis St. Martin's Stomach