Gastric suction is a procedure that empties the contents of the stomach. It may be done for tests, or to remove materials such as poisons.

A tube is inserted through the nose or mouth, down the food pipe (esophagus), and into the stomach. Sometimes you may get a numbing medicine to reduce irritation and gagging as the tube is being inserted.

Stomach contents can be removed using suction right away, or after spraying water through the tube.

In an emergency, such as when a patient has swallowed poison or is vomiting blood, no preparation is needed for gastric suction. When it is done for testing, your doctor may ask you not to eat overnight, or to stop taking certain medications.

You may feel a gagging sensation as the tube is passed.

This test may be performed for several different reasons, including:

• Removing poisons, toxic materials, or overdosed medications from the stomach
• Cleaning the stomach before an upper endoscopy (EGD) in someone who has been vomiting blood
• Collecting stomach acid for tests
• Relieving pressure in someone with a blockage in the intestines

There is a very small risk of the tube being accidentally placed into the airway instead of the esophagus.

Other small risks include the following:

• Aspiration of gastric contents
• Perforation of the esophagus
• Minor bleeding

Greene S, Harris C, Singer J. Gastrointestinal decontamination of the poisoned patient. Pediatr Emerg Care. 2008;24:176-178.