Gastroscopy, also known as an upper gastrointestinal (GI) endoscopy, is a medical procedure used to examine the inside of the oesophagus, stomach, and the upper part of the small intestine (duodenum).

During a gastroscopy, a flexible, narrow tube called an endoscope is inserted through the mouth and guided down the throat into the digestive tract. The endoscope has a light and a camera on its tip, allowing the doctor to visualise the lining of the gastrointestinal tract on a monitor.

A gastroscopy typically takes around 10 to 15 minutes, although it may be longer if additional procedures, such as biopsies or polyp removal, are performed.


Dr Moar will arrange a gastroscopy to further investigate some digestive conditions or symptoms, such as difficulties swallowing, persistent indigestion, heartburn or abdominal pain, nausea or vomiting, vomiting blood, or black and sticky stool that may contain blood.

Sometimes, a gastroscopy is required as part of the diagnostic examination for bariatric surgery.

Preoperative Instructions

Before the procedure, you will be instructed to fast for a certain period to ensure that your stomach is empty. This is important to facilitate a clear view of the digestive tract and reduce the risk of complications.


You will be given a sedative by the anaesthetist to help you relax. The endoscope is then carefully inserted through your mouth and passed down your throat. It may cause some gagging or discomfort, but the sedation helps to minimise any discomfort or pain. You will also be given a mouth guard to protect your teeth and the endoscope.

During the procedure, air or carbon dioxide gas will be introduced into your stomach to help expand it, allowing for better visualisation. The camera at the end of the endoscope transmits real-time images to a monitor, which Dr Moar uses to examine the lining of your oesophagus, stomach, and duodenum. Dr Moar may also perform various interventions, such as taking tissue samples (biopsies) or removing polyps if necessary. Other procedures, such as dilatation (stretching of scar tissue) can be done at the same time in specific circumstances.

Postoperative Instructions

After the procedure, you will be monitored until the sedative effects wear off. You may experience some temporary throat discomfort. It is common to feel bloated or gassy due to the air or carbon dioxide gas introduced during the procedure. You will generally be allowed to go home on the same day, accompanied by a responsible adult who can drive you.

Dr Moar will discuss the findings with you after the procedure or during a follow-up appointment. Biopsy results, if taken, will take a few days to be processed by a laboratory. The results will help in diagnosing any gastrointestinal conditions or evaluating the effectiveness of a treatment.


As with any medical procedure, there are potential risks and complications associated with gastroscopy, although they are rare. These may include bleeding, infection, perforation (a tear in the digestive tract), or adverse reactions to sedation.

Treatment Alternatives

If a gastroscopy is unavailable or unadvisable to you, alternatives include a barium swallow and meal, ultrasound, capsule endoscopy, or CT scan.

Additional Information