Before beginning gastric suction, or stomach pumping, your doctor will give you medicine to numb your throat. Then, after inserting a tube in your mouth or nose, they will use suction to remove your stomach contents.

Gastric suction is a procedure your doctor can perform to empty the contents of your stomach quickly during an emergency. It is also known as gastric lavage and nasogastric tube suction.

Read on to learn more about the procedure, when it’s used, and how it works.

Your doctor may order gastric suction if you’ve swallowed poison or overdosed on pills. If you’ve swallowed something poisonous, such as a household chemical, get to the hospital as soon as possible. Gastric suction is most successful if it’s performed within four hours of ingesting a poisonous substance. Once the poison works its way further into your digestive tract, performing this procedure won’t remove it.

Your doctor may also order gastric suction after certain surgeries on your abdominal area, such as a gastrectomy. This procedure involves the partial or total removal of your stomach. Gastric suction can help keep your stomach empty while you heal. In this case, you won’t be eating solid foods, so only thin liquids will enter your stomach. A low level of suction will be used to remove the fluids.

Your doctor may also use gastric suction to:

  • collect a sample of your stomach acid
  • relieve pressure on your intestines if they’re blocked
  • suction out blood if you’ve had a stomach hemorrhage
  • clean out your stomach if you’re vomiting blood during an upper gastrointestinal (GI) endoscopy, which is a procedure in which your doctor inserts a scope down your esophagus to examine your upper GI tract
  • to safely perform surgery and limit the risk of aspiration pneumonia
  • to decompress the stomach during assisted ventilation in a hospital setting

If you’re undergoing gastric suction because of poisoning, drug overdose, or other emergency situations, you won’t have time to prepare for it beforehand. But if your doctor orders gastric suction to collect a sample of your stomach acid for testing, they may ask you to fast or avoid taking certain medications before the procedure.

Before the procedure, your doctor may give you medicine to numb your throat. This will help decrease gagging and irritation. Then, they’ll insert a lubricated tube into your mouth or nose and thread it down through your esophagus into your stomach. Your esophagus is the tube that connects your mouth to your stomach.

Your doctor may spray water or saline solution down the tube before applying suction. Saline solution can help protect you against electrolyte imbalances that can occur when your doctor removes fluids from your stomach. They’ll then apply suction to remove your stomach contents.

If you have the tube inserted while you’re recovering from abdominal surgery, your doctor will likely leave it in while you heal. A nurse will probably irrigate the tube regularly with saline solution. This helps to keep the tube open and prevent blockages.

This procedure can be uncomfortable. You may feel like gagging while they insert the tube. Afterward, your throat may feel irritated.

This procedure also poses more serious risks. One of the most common is aspiration pneumonia. This happens when some of your stomach contents enter into your lungs or airways. Untreated aspiration pneumonia can potentially lead to lung swelling, lung abscesses, or bacterial pneumonia. The symptoms of aspiration pneumonia include:

  • chest pain
  • wheezing
  • coughing up phlegm
  • a bluish tint to your skin
  • exhaustion
  • a fever

This risk occurs if the tube becomes dislodged. Having gastric suction can protect you from aspiration pneumonia by emptying the stomach before contents can get into the respiratory tract.

Other risks of gastric suction include:

  • spasms of your vocal cords, which temporarily prevent normal breathing
  • the tube entering your airway instead of your esophagus
  • the tube poking a hole in your esophagus
  • stomach contents getting pushed further into your bowels
  • minor bleeding

Talk to your doctor about any concerns you have about this procedure. They can help you understand the potential benefits and risks.