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What is Gastroscopy?

Gastroscopy is a procedure that examines the lining of the oesophagus, stomach and part of the duodenum (part of the 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 gastroscopy 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 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 gastroscopy, he will be watching a monitor. The images from the camera are transmitted and magnified onto a hi-definition monitor. This allows the doctor to see 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.

  • Stop bleeding from ulcers or tumours.
  • Remove foreign body that has been accidentally swallowed e.g. fishbone
  • Perform minor surgery such as cutting out small tumours like polyps or even early stomach cancer.

When is a Gastroscopy recommended?

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

  • Upper abdominal discomfort (dyspepsia)
  • Heartburn or reflux symptoms
  • Unexplained bloating
  • Unexplained weight loss
  • Decrease in appetite
  • Difficulty in swallowing (dysphagia)
  • Anaemia
  • Vomiting of blood or passing out black stools (These are signs of internal bleeding)
  • Screening for stomach cancer in high-risk individuals.

Procedure for 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 increase the chance of food or fluid being vomited into the lung while under sedation.


  • 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 gastroscopy will vary, depending in part on what is found and what is done; on average, the procedure takes about 5-10 minutes..


  • Gastroscopy is usually performed as a day surgery procedure.
  • After the procedure, you will be cared for in a recovery area for about 1-2 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 at the Endoscopy Centre or in our Nexus Surgical clinic. Otherwise, an early date will be given to you to return for a consultation with your doctor.
  • It is essential for you to arrange for a friend or family member to accompany you home. Although you will 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 sore throat.

Consult Our Doctors

Dr Chan Chungy Yip

Dr Chan Chung Yip

HepatoBiliary, Pancreas & General Surgeon

colorectal cancer specialists

Dr Jane Tan Jye Yng

Colorectal & General Surgeon

Lim Khong Hee

Dr Lim Khong Hee

Upper Gastrointestinal, Bariatric & General Surgeon

pancreatic cancer specialist in singapore

Dr Ho Choon Kiat

HepatoBiliary, Pancreas & General Surgeon

Gastroscopy FAQs

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

The estimated cost for a standard diagnostic gastroscopy is divided into 2 components

  1. Doctor’s Fees 
    The doctor’s fees for a diagnostic gastroscopy performed during office hours by Nexus Surgical doctors will be approximately S$600 to S$1000 (excluding prevailing taxes). This range is based on the published Fee Benchmark set up the Ministry of Health of Singapore.

  2. Hospital Fees
    The hospital fees refer to charges levied by the hospital for the use of the instruments as well as the ward/bed and nursing care.

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.

We have a detailed write-up on the cost of endoscopy in Singapore on our website.

A gastroscopy evaluates the inner linings of the oesophagus, stomach, and first portion of the small intestine (known as the duodenum).

If biopsies (samples of tissue) were taken during the gastroscopy, the results will take between 3-5 working days.

During a gastroscopy, the patient will usually be sedated.

During the gastroscopy, an inspection of the throat area is usually done as well. However, if one would like to have a thorough examination of the throat, a detailed assessment by an ENT (Ear Nose & Throat) Specialist is preferred.

A gastroscopy will generally reach the second part of the duodenum.

There is usually no food restriction after a gastroscopy as long as the patient is fully awake from the sedation.

Gastroscopy may be recommended when a patient has the following symptoms:

  1. Difficulty swallowing
  2. Vomiting
  3. Upper abdominal pain or discomfort
  4. Passage of blackish stool
  5. Heartburn or regurgitation
  6. Family history of stomach cancer

A gastroscopy and a colonoscopy can be done in sequence in the same sitting (during the same sedation episode).

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