What is a gastroscopy?

Gastroscopy allows the examination of the esophagus, stomach, and duodenum using a flexible "tube" inserted through the mouth. It helps your doctor to determine the origin of your symptoms. It is currently the gold standard for exploring the esophagus, stomach, and duodenum.

What is gastroscopy used for?

Gastroscopy is used to detect possible lesions and to perform biopsies (collection of tissue samples to be examined under the microscope).


In general, the examination itself lasts less than 10 minutes. When adding the time needed for the paperwork and the rest after the examination, the total duration is about one hour.

How to prepare for it?

In order for the examination to take place under good conditions, the stomach must be empty. You should not eat, drink, or smoke for 6 hours before the examination. Always inform your doctor of any allergies or medications you are taking (especially those affecting blood coagulation such as Aspirin® and Sintrom®). Before the examination, false teeth and glasses must be removed.


The examination uses a flexible device called an endoscope that is introduced through the mouth, after a local anesthesia. Most of the time, you will be lying on your left side. Samples may be taken during the examination if your doctor deems it necessary. Between each patient, the endoscope is disinfected according to the recommendations in force and all the accessories used (biopsy forceps, etc.) are sterilized or discarded (single-use material). It is essential to breathe regularly during the whole examination in order to avoid possible nausea. In addition, you must avoid swallowing your saliva and let it run out of your mouth on a protective cover.

What happens after the procedure?

If you were given a sedative during the examination, the doctor may ask you to rest for one to two hours before leaving the hospital.

Risks and discomforts/Complications/Disadvantages

The examination is painless. The endoscope doesn't impede breathing because it doesn't go into the lungs. During the examination, air is blown in to expand the stomach walls. This may cause some abdominal bloating and small air discharges.


Any medical procedure, exploration, or intervention on the human body, even if carried out in competent and safe conditions in accordance with current medical data and regulations, involves a risk of complications.

Gastroscopy complications are quite exceptional and notably include: perforation, hemorrhage, cardiovascular and respiratory disorders, and infection. They may require hospitalization. These complications may be favored by your medical and surgical history or by the use of certain treatments.

Complications most often appear during the endoscopy but can also occur a few days after (abdominal and chest pain, vomiting of red or black blood, cough, fever, chills, etc.). In this case, it is very important to contact the doctor who took care of you immediately at the following telephone number: 02/764 28 23 or 02/764 11 11 and ask for the person call 4 28 39. If you are unsuccessful in contacting him/her, it is imperative that you contact your treating physician as soon as possible.


Gastroscopy is the best method for examining the esophagus, stomach, and duodenum. X-ray of the stomach, performed after swallowing an agent that is opaque to X-rays, is possible but doesn't provide as many details, and it doesn't allow to take samples or to perform a treatment. Drugs are often granted reimbursement based on endoscopy, but not on radiography. CT scan and ultrasound do not replace gastroscopy. If the examination your doctor has suggested is not done, it can have harmful medical (undiscovered curable disease) or financial (unreimbursed medications) consequences.

The return home

If you have been given a sedative, which is often the case, you should not drive a vehicle or engage in any dangerous activity on the day of the exam, as sedatives can impair your reflexes or your judgment. For the same reasons, you are also advised not to make important decisions that require your full lucidity on the day of the exam.


Hepato-gastroenterology consultation secretariat

+32 2 764 28 23
Floor: -2 Road: 606