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Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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In this Article

• What is Helicobacter pylori?
• What does H. pylori cause in humans?
• What are the symptoms of H. pylori infections?
• Is H. pylori contagious?
• How is H. pylori infection diagnosed?
• Why treat H. pylori?
• What is the treatment for H. pylori?
• Who should receive treatment for H. pylori?
• Can H. pylori infections be prevented?
• What is the prognosis for H. pylori infections?
• Patient Comments: Helicobacter Pylori - Treatments
• Patient Comments: Helicobacter Pylori - Diagnosis
• Find a local Gastroenterologist in your town
• Helicobacter Pylori Index

H. pylori infections start with a person acquiring the bacterium from another person (via either the fecal-oral or oral-oral route). Although the majority of individuals that have these bacteria in their GI tracts have few if any symptoms (see symptoms), most people develop stomach inflammation (gastritis) from the body's response to the bacterium itself and to a cytotoxin termed Vac-A, a chemical that the bacterium produces. Researchers also suggest that the stomach acid stimulates the bacterium in addition to the cytotoxin, and increases invasion of the lining of the stomach, inflammation, and ulcer formation. Other investigators have shown that these bacteria and their products are associated with alterations in the lining cells that are associated with stomach and other cancers, although these are infrequently seen diseases.

The frequency of people infected may somehow be related to race. About 60% of Hispanics and about 54% of African Americans have detectable organisms as compared to about 20%-29% of Anglo Americans. In developing countries, children are very commonly infected.

Most individuals infected with H. pylori have few or no symptoms. They may experience a few episodes of gastritis (minor belching, bloating, nausea, vomiting, abdominal discomfort), but little or nothing else. Often, these symptoms simply cease. However, those individuals who have a more serious infection exhibit symptoms of stomach and duodenal ulcers or gastritis which include the following:

• Abdominal pain and/or discomfort that usually does not wax and wane
• Nausea and vomiting sometimes with blood or coffee-ground like vomitus
• Dark or tar-like stools (black color of feces due to bleeding ulcers)
• Fatigue
• Low red blood cell count due to bleeding
• Full feeling after a small amount of food; decreased appetite that is more constant

Symptoms of black, tarry stools and fatigue should cause a person to seek medical help or go to an emergency department to be evaluated for intestinal bleeding.