What is Gastroscopy?

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Gastroscopy is a technique that allows the upper digestive tract to be viewed directly. This part of the digestive tract runs from the mouth to the second part of the duodenum, which is the start of the small intestine. The gastroscope passes through the oesophagus and stomach.

How it is performed?

To perform a gastroscopy, a thin, flexible tube is inserted through the mouth and is moved into the oesophagus, stomach and duodenum. 

This instrument, known as a gastroscope, is about as wide as a little finger and consists of a lens and a light source. It allows images to be viewed on a video monitor.  

Furthermore, the gastroscope contains an inner channel through which material can be introduced for treatment, for example injecting medication or taking tissue biopsies.

Why is it recommended?

Gastroscopy is recommended as a test to prevent and detect oesophageal and stomach cancer, as well as to evaluate symptoms of reflux, abdominal discomfort, anaemia and chronic diarrhoea, among many others.

How do you prepare yourself?

In general, preparation consists of fasting for 8 hours prior to the test (no solids or liquids may be ingested). Someone needs to accompany the patient for the gastroscopy, as either sedation or anaesthesia will be administered.

Can you take medication?

Most medicines can continue to be taken as usual. 

You must inform your healthcare team about any medication you are taking, particularly products containing aspirin, anti-inflammatory drugs, anticoagulants (such as warfarin, dabigatran, apixaban or heparin), clopidogrel or other antiplatelet drugs. If you are taking insulin or iron, you must also mention this to your healthcare team.  

Furthermore, the patient should inform the team if they have an allergy to any medication.

What happens during the test?

The patient should be positioned on their left side on a stretcher. A catheter is placed in a vein in the hand or arm to administer the anaesthesia, and electrodes are placed to monitor vital signs.  

In most cases, general anaesthesia is administered for rapid elimination, as the distension of the stomach walls and the movement of the gastroscope through certain bends or difficult points can cause abdominal discomfort. This means that no pain is felt during the test.  

In order to see the mucosa well, the doctor will introduce gas (C02) into the stomach. 

The gastroscope is slowly introduced into the oesophagus and stomach via the mouth until it reaches the second part of the duodenum and the surface is examined. As the gastroscope is slowly withdrawn, the digestive tract is re-examined so that no areas remain unseen.

How long does it last?

Generally speaking, the procedure takes less than 15 minutes. If you take preparation and recovery into account, it takes around 25 minutes.

What happens if the gastroscopy shows an abnormality?

In cases where further evaluation is needed, a forceps is passed through the gastroscope to obtain a biopsy. This procedure involves removing a small sample of the mucosal lining from the oesophagus, stomach or duodenum. Biopsies are used to identify various conditions, which means they are often performed even when there is no suspicion of cancer.  

When gastroscopy is used to identify bleeding sites, medications can be injected through the gastroscope channel, or bleeding vessels can be sealed using heat treatment (a cauterisation process involving the application of high temperatures) or by using small clips.  

If polyps or other lesions are found during the examination, they can be removed immediately.

What happens after the Gastroscopy?

The patient remains under observation until the majority of the effects of the sedative or anaesthetic have worn off (this tends to take around 5 minutes). This is why the patient is advised to take someone with them to the hospital. 

In general, it is possible to eat after gastroscopy, although in cases where large polyps have been removed (polypectomy), a special diet and restrictions on certain activities will be necessary.   

The healthcare team will then explain the test results. It is normal to wait a certain length of time (between 10 and 14 days) to obtain the results of the biopsies. 

What are the potential complications?

Gastroscopy and polypectomy do not usually lead to complications. A possible complication that may arise is a perforation or tear in the wall of the oesophagus, stomach or duodenum, but this is extremely rare.  

There may also be slight bleeding in the area where the biopsy was performed or the polyp was removed. This bleeding may stop on its own or be controlled through the gastroscope. It rarely requires follow-up treatment. Some patients may have a reaction to the sedatives, or complications if they have cardiac or pulmonary disease.  

Although complications following gastroscopy are uncommon, it is important to recognise the early signs of potential complications. In this case, the patient is advised to immediately contact the medical team if they notice intense abdominal pain, fever and chills, or blood in their vomit.  

Substantiated information by:

Gloria Fernández Esparrach
Henry Nelson Cordova Guevara

Published: 9 December 2021
Updated: 9 December 2021


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