(also known as OGD for short)

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What is a gastroscopy?

Gastroscopy is a procedure that examines the lining of oesophagus, stomach and part of duodenum (first part of small intestine), and is therefore able to diagnose diseases of the oesophagus and stomach. This procedure uses a highly advanced flexible tube called the gastroscope. The gastroscope has a light source and a tiny high-definition video camera attached at its end.


The doctor will insert this tube through your mouth and guide it down your oesophagus (also called the gullet) into your stomach and then into the duodenum. You will be given some drugs to make you sleep and hence you will be quite comfortable during the procedure. You may not even be aware of the procedure.


As the doctor inserts in the gastroscope, he will be watching a monitor. The images from the camera are transmitted and magnified onto a high-definition monitor. This allows the doctor to see exactly the inside of your oesophagus and stomach, including very small abnormalities due to the magnification.


Besides diagnosing diseases, the gastroscope can be used for treating certain problems. It can be used to stop bleeding from ulcers or tumours. It can be used to remove foreign body that has been accidentally swallowed e.g. fishbone. It can even be used to perform minor surgery such as cutting out small tumours like polyps or even early stomach cancer.

When would the doctor recommend a gastroscopy to a patient?

Some of the common symptoms or problems that will cause the doctor to recommend a gastroscopy includes:

Upper abdominal discomfort (also called dyspepsia)

Heartburn or reflux symptoms

Unexplained bloating

Unexplained weight loss

Decrease in appetite

Difficulty in swallowing (also called dysphagia)

Anaemia (the patient’s haemoglobin level is low)

Vomiting of blood or passing out black stools (these symptoms suggest internal bleeding)

Screening for stomach cancer in high-risk individuals.


Before the gastroscopy
  • Your doctor will first take an informed consent during which he / she will describe the procedure, the benefits as well as the risks involved, as well as alternative methods to check your oesophagus, stomach and duodenum.
  • You will be asked not to eat or drink anything for up to four to six hours before the gastroscopy. It is important for your stomach to be empty as otherwise the food will block the view. This will also decrease the chance of food or fluid being vomited into the lungs while under sedation (called aspiration).
During the gastroscopy
  • The gastroscopy is typically performed at the Endoscopy Centre.
  • At the Endoscopy Centre, the nurse will spray a medication to the back of your throat to numb it, so that you will not retch when the gastroscope is inserted.
  • An intravenous cannula will be placed into a vein at your hand so as to allow us to administer the drugs to sedate you.
  • Your parameters (blood pressure, heart rate and blood oxygen level) will be monitored before, during and after the procedure.
  • A plastic mouth guard will be placed between your teeth to guard your teeth and the scope.
  • You will be asked to lie on your left side.
  • Once you are fully sedated, your doctor will gently pass the scope into your mouth.
  • As the scope is advanced, air will be introduced so as to allow the doctor to see better. You may therefore experience bloating and the urge to belch. Otherwise, you should feel little or no discomfort.
  • The gastroscope has channels that allow the doctor to obtain biopsies (small pieces of tissue) or perform other treatments (such as removal of polyps), or stop bleeding from ulcers, depending on what is found during the examination.
  • The time needed for an OGD will vary, depending in part on what is found and what is done; on average, the procedure takes about 5 to 10 minutes.
After the gastroscopy
  • Gastroscopy is usually performed as a Day Surgery procedure.
  • After the procedure, you will be cared for in a recovery area for about 1 to 2 hours. When you are fully awake, light refreshments will be served.
  • When you are fully awake, your doctor will discuss with you the findings of the gastroscopy. This may be done in the Endoscopy Centre or in our Nexus clinic. Otherwise, an early date will be given to you to return for a consult with your doctor.
  • It is essential for you to arrange for a friend or family member to accompany you home. Although you will be awake by the time of discharge, the sedatives may have a lingering effect. In addition, your ability to make decisions may be impaired.
  • The most common discomfort is a feeling of bloating. This usually resolves quickly within 24 hours. Some patients may complain of mild sorethroat.

Is gastroscopy a safe procedure?

The gastroscopy is a very safe procedure. Nonetheless, although very rare, complications can occur. The overall complication rate is about 1 in 1000 patients.

How much does a gastroscopy cost?

The estimated cost for the gastroscopy is divided into 2 components: the doctor’s fees and the hospital fees. The hospital fees refer to charges levied by the hospital for the use of the instruments as well as the ward / bed.


The doctor’s fees for a diagnostic gastroscopy performed during office hours by Nexus Surgical Associates doctors will be approximately S$600 to S$1000 (excluding taxes). For Singaporeans and Permanent Residents, Medisave may be used to pay part of or all of the bill (conditions apply). As for patients wishing to claim from their health insurance policies, it is best to enquire with your insurance agents first.

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