A gastric tissue biopsy is an examination of a sample of gastric (stomach) tissue for culture (checking for the presence of infection-causing organisms). The test is done to look for  the presence of certain microorganisms that may be playing a role in certain diseases.

Gastric tissue biopsy is obtained via a procedure known as an upper endoscopy. You may be given a sedative (medicine to make you drowsy), or narcotic (powerful pain-killing medicine), to relieve anxiety and discomfort before this test. A local anesthetic (numbing medicine) is sprayed into the mouth and throat area.

A flexible tube is passed through the mouth, down the esophagus (the food pipe), and enters the stomach. The tube may pass through to the duodenum if necessary. The tube allows the health care provider to see the various parts of the upper intestinal tract and take tissue samples of certain areas. The samples are then sent for laboratory and pathology examination.

No food or fluid may be ingested for 6 to 12 hours before the test.

For infants and children:

The preparation you can provide for this test depends on your child's age and experience. For specific information regarding how you can prepare your child, see the following topics:

• infant test or procedure preparation (birth to 1 year)
• toddler test or procedure preparation (1 to 3 years)
• preschooler test or procedure preparation (3 to 6 years)
• schoolage test or procedure preparation (6 to 12 years)
• adolescent test or procedure preparation (12 to 18 years)

You may feel a gagging sensation as the tube is passed down to your esophagus. You may also feel cramping and a feeling of fullness if air is introduced to expand an area. You may have a sore throat after the procedure.

An endoscopy may be performed to determine the presence of ulcers, for which pathology and culture specimens are often useful. It also aids in the diagnosis of cancers and other conditions. Certain infections may also be diagnosed by endoscopy; therefore, a culture of tissue obtained by endoscopy may be done.

The acidity of the stomach provides a major barrier to excessive growth of microorganisms. The presence of certain bacteria (for example, Helicobacter pylori) or other microorganisms (such as Giardia) is abnormal.

The culture obtained from a gastric biopsy can detect certain infection-causing microorganisms, such as Helicobacter pylori, which plays a role in ulcer disease.

The risks of endoscopy include a small risk of perforation (hole) in the stomach or esophagus, and bleeding.

A sample sent for pathology, to be examined under a microscope, is also important, in addition to culture, for the diagnosis of certain conditions.