The test is done in a gastroenterology laboratory. A nasogastric (NG) tube is passed through one side of your nose and into your esophagus. Mild hydrochloric acid will be sent down the tube, followed by salt water (saline) solution. This process may be repeated several times.

You will be asked to tell the health care team about any pain or discomfort you have during the test.

You will be asked not to eat or drink anything for 8 hours before the test.

You may have a gagging feeling and some discomfort when the tube is put in place. The acid may cause symptoms of heartburn. Your throat may be sore after the test.

The test tries to reproduce symptoms of gastroesophageal reflux (stomach acids coming back up into the esophagus). It is done to see if you have the condition.

The test results will be negative [no symptoms of gastroesophageal reflux disease (GERD)].

A positive test shows that your symptoms are caused by esophageal reflux of acid from the stomach.

There is a risk of gagging or vomiting.

Acid perfusion test

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Kavitt RT, Vaezi MF. Diseases of the esophagus. In: Flint PW, Francis HW, Haughey BH, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 68.

Pandolfino JE, Kahrilas PJ. Esophageal neuromuscular function and motility disorders. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 44.

Updated by: Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.