Gastroscopy

Medically written by
A/Prof Viraj Kariyawasam
MBBS, FRACP, MRCP, PhD
Gastroenterologist & Hepatologist
Associate Professor – Macquarie University
Head of IBD Service – Blacktown Hospital
Last reviewed: March 2026

1. What is a Gastroscopy?

Gastroscopy, also known as upper endoscopy, is a procedure used to examine the lining of the oesophagus, stomach, and the first part of the small intestine (duodenum). A thin, flexible tube with a camera on the end is passed gently through the mouth to allow direct visual assessment of the upper digestive tract.

Gastroscopy is commonly performed to investigate symptoms such as heartburn, difficulty swallowing, upper abdominal pain, nausea, vomiting, unexplained weight loss, anaemia, or bleeding. It is also used to monitor known conditions such as Barrett’s oesophagus or stomach ulcers. It is also used to assess for conditions such as oesophagitis, Barrett’s oesophagus, stomach ulcers, coeliac disease, and upper gastrointestinal cancers.

2. What Happens During a Gastroscopy?

Before the procedure, you will be asked not to eat or drink for several hours to ensure the stomach is empty. You should inform your doctor about any medications, allergies, or medical conditions.

A local anaesthetic spray may be used to numb the throat, and sedation is usually given through a vein to help you relax. The gastroscope is then passed gently through the mouth and into the stomach. Air is introduced to improve visibility, and small tissue samples (biopsies) may be taken. The procedure usually takes 10 to 20 minutes. In some cases, gastroscopy may be performed without sedation depending on patient preference and clinical circumstances.

3. Recovering From a Gastroscopy

After the procedure, you will be monitored until the effects of sedation wear off. You may experience a mild sore throat, bloating, or discomfort, which usually resolves quickly. Biopsy results are usually available within several days and will be discussed at follow-up.

Because of the sedation, you should not drive, operate machinery, or make important decisions for the rest of the day. Most people can resume normal eating later the same day unless advised otherwise.

4. Risks of Gastroscopy

Gastroscopy is a very safe procedure, and serious complications are uncommon. Possible risks include minor bleeding after biopsies, reaction to sedation, infection, or very rarely a tear in the oesophagus or stomach.

You should seek urgent medical attention if you develop severe chest or abdominal pain, persistent vomiting, fever, or black stools after the procedure.