Gastroscopy: when you need it and what happens

A gastroscopy is an investigation of the first part of your digestive system, from your gullet (oesophagus) down into your stomach and the first part of your small intestines (duodenum). 

It involves passing a thin, telescope-like tube (gastroscope) with a light and a camera on the end through your mouth so that your doctor can capture video images of the inside of your digestive system. During a gastroscopy, tissue samples (biopsies) can also be collected and certain treatments performed. 

Reasons to have a gastroscopy

Common reasons that your doctor may recommend a gastroscopy is if you have persistent acid reflux or heartburn that is affecting the quality of your life. 

Other reasons to investigate your digestive system via a gastroscopy include persistent abdominal pain, nausea or vomiting, difficulty swallowing (dysphagia) and anaemia. 

Who can have a gastroscopy?

Most people can safely have a gastroscopy, unless you have a medical condition that makes it risky for you.

A gastroscopy is not recommended if you’ve had a recent heart attack as this can stress your heart and increase your risk of another heart attack.

In rare cases of a perforation (hole) in your digestive system, a gastroscopy is also not suitable as it may worsen the damage.

What happens if you can’t have a gastroscopy?

If you’re unable to have a gastroscopy, your doctor may recommend a CT scan or a barium swallow. A barium swallow involves drinking a special dye, followed by a series of X-rays to image your digestive system. 

Depending on your symptoms, your doctor may recommend other tests, such as an oesophageal pH test.

Preparing for a gastroscopy

Your care team will ask that you do not eat or drink anything for six hours before your gastroscopy to help empty your stomach. This will reduce the risk of your stomach contents entering your windpipe (aspiration) during your gastroscopy.

You may also be told to temporarily stop taking certain medications in the lead up to your gastroscopy. For example, you may be asked to stop taking blood thinning medication to reduce the risk of bleeding during your gastroscopy.

Your gastroscopy procedure

A gastroscopy is a day case investigation, which means you can return home on the same day. Make sure you wear loose, comfortable clothing as you will be asked to lie down on your side.

You will be given an anaesthetic spray to numb your throat, which will help reduce your gag reflex when the gastroscope is passed into your mouth. You will also be given a mouth guard to protect your teeth.

You will have the option of a sedative to help you relax — this will be given via an intravenous line into a vein in your arm. If you choose to have a sedative, you must have someone to take you home and stay with you for the next 24 hours until the effects of the sedative have worn off.

A gastroscopy usually takes around 10 minutes. If your gastroscopy is purely investigative ie no biopsy or treatment is performed, you can eat and drink as normal immediately afterwards. If you have a biopsy or treatment it may take longer and your care team will provide you with advice on what to eat and drink, and when.

Risks of a gastroscopy

Gastroscopy is generally considered a safe procedure and serious complications are rare. If you have a biopsy or treatment, there is a small risk of bleeding.

Other rare complications include damage to the oesophagus or stomach (eg perforation) — this is more common when treatment is being carried out, for example, on a narrowed oesophagus. There is also a small risk of aspiration or choking.