Stomach acid test

Definition

The stomach acid test is used to measure the amount of acid in the stomach. It also measures the level of acidity in stomach contents.

How the Test is Performed

The test is done after you have not eaten for a while so fluid is all that remains in the stomach. Stomach fluid is removed through a tube that is inserted into the stomach through the esophagus (food pipe).

A hormone called gastrin may be injected into your body. This is done to test the ability of the cells in the stomach to release acid. The stomach contents are then removed and analyzed.

How to Prepare for the Test

You will be asked not to eat or drink for 4 to 6 hours before the test.

How the Test will Feel

You may have some discomfort or a gagging feeling as the tube is inserted.

Why the Test is Performed

Your health care provider may recommend this test for the following reasons:

Normal Results

The normal volume of the stomach fluid is 20 to 100 mL and the pH is acidic (1.5 to 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour (mEq/hr) in some cases.

Note: Normal value ranges may vary slightly depending on the lab doing the test. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may indicate:

Risks

There is a slight risk of the tube being placed through the windpipe and into the lungs instead of through the esophagus and into the stomach.


Review Date: 10/27/2018
Reviewed By: Michael M. Phillips, MD, Clinical Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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