Gastroscopy (OGD)



Gastroscopy (OGD)


Gastroscopy is sometimes known also as an upper GI endoscopy. It is a procedure to examine the esophagus, stomach and the start of the small intestine (duodenum) with the use of an instrument called the gastroscope. The gastroscope has a long, thin and flexible tube with camera systems and capabilities to perform procedures such as biopsy and removal of polyps.

It is done by a gastroenterologist, who is a specialist with years of special training. It is usually done in the endoscopy center or operating theater of the hospital. Usually, the examination is done under moderate sedation, which means that you are “sleeping” during the procedure and will not remember the procedure.

Most of the time, gastroscopy is superior to X-rays, since the doctor can see more clearly.


The endoscopist passes the gastroscope through the esophagus into the stomach and duodenum. The upper digestive tract is washed clean and examined in detail. The examination would also involve the use of narrowband imaging (special light) to detect pathology that would otherwise be invisible. Various procedures can be performed through instruments that are passed through the gastroscope:

  • Biopsies: These would be done in a systematic manner or guided by enhanced imaging systems
  • Polypectomy: large polypoidal lesions can be removed with the use of endoscopic snares.
  • Injection of glue: histoacryl glue injection can be used to stop bleeding from abnormally enlarged vessels in the stomach called gastric varix.
  • Argon-plasma-coagulation (APC) can be used to obliterate small bleeding vessels or lesions.
  • Hemoclip application: Commonly used to stop bleeding from arteries.
  • Hemospray can be used to stop upper digestive tract bleeding.
  • Ligation of esophageal varices (abnormal enlarged blood vessels in the esophagus) to stop or prevent bleeding
  • Removing foreign body
  • Inserting feeding tubes
  • Performing dilatation and stenting (for the advanced endoscopist only)


The gastroscopy helps with the diagnosis and assessment of digestive illness such as:

  • Stomach ulcer or duodenal ulcer
  • Cancer of the esophagus and stomach
  • Gastroesophageal reflux disease (GERD)
  • Gastritis
  • Gastric polyps
  • Iron deficiency anemia

It can also aid to sort out symptoms such as:

  • Heartburn
  • Difficulty swallowing
  • Persistent or recurrent vomiting
  • Bloatedness
  • Epigastric pain
  • Weight loss

Preparing for Gastroscopy

You should fast for at least 6 hours prior to your gastroscopy. Longer fasting may be needed if your doctor suspect that your stomach is not emptying properly. You may drink clear fluid up to 2 hours before the procedure but milk is not allowed during the fasting.

In general, most medication should be continued before the gastroscopy with the exception of diabetes medication and blood thinners. Diabetic medication should be omitted during the fasting. You should check with your doctor if your blood thinner needs to be discontinued prior to the procedure.

As you will be given medication to make you sleepy, you must not drive, work or make any important decision after the procedure. Medical Certificate will be issued if needed and you should rest at home for the rest of the day.

Before the Gastroscopy

A nurse will conduct final checks, and bring you into the procedure room. An intravenous line will be inserted.

During the Gastroscopy

A throat spray will be administered to lessen the discomfort of the procedure.

You will be lying on your left, with your legs curled up and a plastic bite will be placed between your teeth to protect your teeth.

Sedation will then be given. After you have fallen asleep, the procedure will begin. You will likely not remember any of the procedure. You will be breathing on your own and monitored closely during the procedure.

You will wake up gradually after the procedure is done. All the medication used for sedation have a duration of action of a few minutes.

After the Gastroscopy

You will be cared for in a recovery area or room. The nurses will give you food and drink when they assessed that you are ready. You should arrange for a family member to take discharge instruction and take you home. You should only resume working and driving the following day.

Sometimes, you may have a mild sore throat, bloating and cramp. This normally goes away after 24 hours.


Gastroscopy is a very safe examination. Complication happens only very rarely.

Despite the best of intention and effort, sometimes issues do happen. There are:

  • A tear in the intestinal wall (which may need surgery to fix)
  • Bleeding
  • Allergic reaction to medication

If you have any concern after the gastroscopy, you should contact your doctor.


Quality of the gastroscopy depends mainly on the doctor conducting the examination. The doctor should be well trained in a recognized institution and have done adequate numbers.

A good documentation should have an adequate number of pictures to cover the entire upper GI tract. The picture should be clear and of good quality. The stomach should be well distended  and washed clean to enable proper examination. Image enhancement should be used when appropriate. Labeling of the pictures is also helpful.

Under adequate sedation, there should be minimal discomfort during the procedure. The doctor should also ensure that the sedation is carried out in a safe manner. There should be adequate monitoring after the procedure.

Rarely, you may have complications that needs care that only a hospital can provide. Easy access to a hospital is preferable.

Cost Of Gastroscopy and How to Choose

A certain proportion of the cost of gastroscopy is covered with Medisave deduction in Singapore. Many company health insurances and private health insurances also will cover the cost of the procedure. Most gastroscopies are done with diagnostic intent so you should choose specialist specialized in sorting out digestive symptoms. In Singapore’s context, such specialist would be a gastroenterologist.

Click here to find out on the preparation of your procedure. 

Endoscopy, Services, Stomach Illness

Facebook | Twitter | LinkedIn | Instagram

All Rights Reserved, gutCARE | Sitemap