A gastroscopy is performed when the patient may be experiencing stomach pain, feeling sick, vomiting or having difficulty swallowing. It is also used to treat conditions of the food pipe, stomach and duodenum (small bowel leading from the stomach). Your doctor can pass instruments down the endoscope and treat many problems with little or no discomfort.

Your doctor may stretch a narrowed area, remove small non-cancerous growths, or treat bleeding. The doctor can also treat bleeding by injecting drugs, sealing off blood vessels using heat or other methods such as small clips. The doctor may take pieces of tissue. This is known as a biopsy. These can allow detection of ulcers or cancers.

Pre-operative Instructions

You must not eat or drink anything for at least six hours before the procedure. This is to make sure that you have an empty stomach, which is necessary for the safest examination.


The doctor may start by spraying your throat with a local anaesthetic. You will be given sedation to help you relax. The doctor looks at the lining of your food pipe (oesophagus), stomach and duodenum (first part of the small bowel via a thin, bendable tube called an endoscope which has a camera attached. Your insides can then be seen on a video screen. You’ll then lie on your left side, and your doctor will pass the tube into your mouth and down your food pipe (oesophagus), stomach and duodenum (small bowel leading from the stomach).

The endoscope does not cause problems with breathing. Most patients find the test only a bit uncomfortable, and many patients fall asleep.

Post-operative Instructions

You will be watched until most effects of the drugs have worn off. Your throat may be a little sore, and you might feel bloated. The air put into your stomach during the test causes this.

You can usually eat and drink normally afterwards unless you are told otherwise. You doctor will explain the results of the examination to your or arrange for you to come back to clinic and talk to you about the results.


There are some risks/complications which include:

  • A tear (perforation) through the wall of the food pipe, stomach and duodenum. This is rare and may need surgery. There is also a risk of infection. This may result in a longer stay in the hospital.
  • Bleeding at a biopsy site or at the site where a polyp has been removed. This is usually minor and can usually be stopped through the endoscope. Rarely, surgery is needed to stop the bleeding.
  • Aspiration is uncommon and is due to vomit going into the lungs.
  • Your procedure may not be able to be finished due to problems inside your body or because of technical problems.
  • There is a rare possibility that defects or disease may be missed.
  • Other potential risks include a reaction to the sedation used and complications from heart or lung diseases.
  • Death is a complication from gastroscopy but is extremely unlikely but possible.