What happens during a gastroscopy?

A gastroscopy (examination of the stomach) can help confirm or rule out the presence of medical conditions like gastritis or peptic ulcers. In this procedure, an instrument called a gastroscope is used to look at the inside of the food pipe, the stomach, and part of the duodenum (the first part of the intestine).

Gastroscopy may be done if you have the following:

  • Chronic or recurring heartburn, nausea or vomiting
  • Nausea over a longer period of time
  • Stomach pain
  • Trouble swallowing
  • Black stool or blood in your stool
  • Weight loss for no apparent reason
  • Suspected peptic
  • Suspected cancer of the esophagus or stomach
  • A check-up after stomach surgery

A gastroscope is a flexible tube that has a small light and a video camera attached to the end of it. The images from the video camera are sent to a screen. The tube can be used to take tissue samples by inserting instruments such as small pincers. It can also be used to suck out air and fluids.

How can you prepare for a gastroscopy?

Before a gastroscopy, your doctor will tell you about the procedure and any associated risks. This includes information about medication you can take to make the examination more comfortable. If you take medication regularly, you should ask beforehand whether and when to take it on the day of the procedure. You may need to stop taking some medications, such as anti-clotting medication, several days before the gastroscopy. Your doctor will tell you how many hours before the gastroscopy you should stop eating and drinking. Before the procedure you will be asked to sign a consent form.

If you are given a sedative for the gastroscopy, you will usually not be allowed to drive a car or operate machinery for 12 to 24 hours afterwards. The exact amount of time will depend on the medications used. Your doctor will give you more information. Ideally, you should be picked up by someone or take a taxi home after the procedure.

What does the procedure involve?

Shortly before the gastroscopy, your mouth and throat will be anesthetized using a spray. Any removable dentures need to be taken out before the procedure. You may be given a sedative. In Germany, the sedatives most commonly used for this purpose are called propofol and midazolam. They are injected into a vein and make you sleep for a short while.

Gastroscopy generally lasts about 5 to 10 minutes. You will usually lie on your left side. A small tube or a protective ring is put between your teeth so your mouth stays open and you do not bite the gastroscope. First you have to swallow so the gastroscope can enter your esophagus (food pipe). Then it is slowly pushed into your stomach and down to the entrance of your duodenum.

Using the video images, your doctor can examine your food pipe and stomach lining to look for redness or inflammations. Things like bleeding, varicose veins, unusually narrow passages and stomach ulcers can also be seen on the screen. If necessary, a tissue sample will be taken. This is not painful.

Bleeding, unusually narrow passages, and certain medical conditions can be treated directly during the procedure.

What are the possible risks or complications of a gastroscopy?

You may have a sore throat or a numb feeling in your mouth after a gastroscopy, caused by the anesthetic spray. Because the doctor may have pumped some air into your stomach in order to see more, you may feel full for a short while. Complications like bleeding and injury to organs are very rare. If your teeth are not firmly attached, the gastroscope may cause damage to your teeth when it is put into your mouth. Only in very rare cases do sedatives lead to complications such as breathing problems or cardiovascular problems.

Although the sedatives only cause you to sleep for a short while, you may still have trouble concentrating and feel tired for several hours afterwards.

American Society for Gastrointestinal Endoscopy (ASGE). Appropriate use of GI endoscopy. Gastrointest Endosc 2012; 75(6): 1127-31. 

American Society for Gastrointestinal Endoscopy (ASGE). Adverse events of upper GI endoscopy. Gastrointest Endosc 2012; 76(4): 707-18.

Deutsche Gesellschaft für Verdauungs- und Stoffwechselkrankheiten (DGVS). S3-Leitlinie „Sedierung in der gastrointestinalen Endoskopie“ 2008. (AWMF-Leitlinien; Band 021 - 014).

Messmann, Helmut. Klinische Gastroenterologie. Stuttgart: Thieme; 2011.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on June 30, 2015
Next planned update: 2021


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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