Normally the volume of the stomach fluid is 20 to 100 mL and the pH is acidic (1.5 to 3.5). In some situations, these numbers are converted to actual acid production in units of milliequivalents per hour.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results mean
Decreased levels of stomach acid or gastrin can cause malabsorption.
The presence of bile in the stomach indicates material is backing up from the small intestine ( duodenum). This may happen after part of the stomach is removed with surgery.
What the risks are
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. The health care provider will be sure the tube is correctly placed before continuing with the test.
Scubert ML, Kaunitz JD. Gastric secretion. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 49.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.