Gastroscopy

What is gastroscopy?

A gastroscopy (sometimes called an upper endoscopy, or an OGD — oesophago-gastro-duodenoscopy, if you want the full name) is a straightforward examination where a thin, flexible tube with a tiny camera on the end — called a gastroscope — is gently passed through your mouth, down your throat, and into your stomach and the first part of your small intestine (called the duodenum). The camera sends back live, high-definition images that give Mr Nguyen a very clear view of the lining of your entire upper digestive tract in real time.

The whole procedure usually takes between 10 and 20 minutes. Before it starts, you will be given light sedation through a small drip in your hand, so you will be comfortable and relaxed throughout — most patients are genuinely surprised by how little they felt or remembered afterwards. If Mr Nguyen finds anything that needs attention, small tissue samples (biopsies) can be taken or minor problems can be treated right then, without needing a second procedure.

When is gastroscopy recommended?

A gastroscopy is often suggested when you have symptoms that could be coming from your oesophagus (the tube that carries food from your throat to your stomach), your stomach itself, or the top of your small intestine. You might be wondering if that is you — here are the most common reasons Mr Nguyen recommends it:

• Persistent heartburn or acid reflux — where stomach acid keeps rising up into your throat, causing a burning sensation or a sour taste, and it has not settled with medication
• Difficulty swallowing (called dysphagia) — a feeling that food or liquid is getting stuck partway down as you swallow
• Pain or discomfort in your upper abdomen, particularly after eating
• Unexplained nausea, vomiting, or unintentional weight loss
• Suspected bleeding from the upper digestive tract — for example, vomiting blood or passing very dark, tar-like stools, which can indicate old blood from further up
• Iron deficiency anaemia (low iron in your blood with no obvious explanation) — often investigated at the same time as a colonoscopy, since bleeding can sometimes come from either end of the digestive tract
• Monitoring of Barrett's oesophagus — a condition where the cells lining the lower oesophagus have changed due to long-term acid exposure, and which needs regular check-ups
• Suspected peptic ulcers (sores on the lining of your stomach or duodenum) or a Helicobacter pylori infection (a common stomach bacterium that can cause ulcers and is very treatable once identified)
• Assessing a hiatus hernia — where part of your stomach has pushed upward through the opening in your diaphragm — before deciding whether surgery is needed

What to expect

Not knowing what is going to happen is often the most nerve-wracking part. Here is a clear, step-by-step picture of what your day will look like.

When you arrive, the friendly nursing team will check you in, place a small drip (IV line) in your hand or arm, and run through a few questions about your health and medications. If you wear dentures or a dental plate, you will be asked to remove these before the procedure begins — they can be safely stored for you.

Once you are lying comfortably on the procedure trolley, the light sedative is given through your drip. Within a minute or two you will feel drowsy, calm, and relaxed — the sedation does not put you fully to sleep, but most people are pleasantly drowsy and barely aware of what is happening. A small plastic mouthguard is placed gently between your teeth — this protects both your teeth and the camera tube. A local anaesthetic spray is also applied to the back of your throat to reduce any gagging reflex.

Mr Nguyen then guides the gastroscope — a thin, flexible tube roughly the width of your little finger — through the mouthguard, down your throat, and into your stomach and the first part of your small intestine. You may feel a little pressure or mild bloating from the small amount of air used to open up the space — this is completely normal, passes quickly, and is not painful. The examination itself takes around 10 to 20 minutes.

Most people are genuinely surprised by how little they remember of the whole thing. You will come around in the recovery area shortly afterwards, perhaps feeling a little groggy for a short while, but not in pain. The nursing team will keep an eye on you until you are ready to go home.

What can be found and treated?

A gastroscopy can pick up — and often treat — a wide range of conditions in the upper digestive tract. Here is what Mr Nguyen commonly finds, and what each one means for you:

• Gastro-oesophageal reflux disease (GORD) and oesophagitis — inflammation of the lining of the oesophagus caused by stomach acid repeatedly flowing back up. Seeing this directly helps Mr Nguyen assess how severe it is and guide your treatment
• Hiatus hernia — where part of your stomach has pushed upward through the hole in your diaphragm (the sheet of muscle below your lungs). This is very common and often manageable without surgery
• Barrett's oesophagus — a change in the cells lining the lower part of the oesophagus, caused by years of acid damage. It is not cancer, but it does need regular monitoring because in a small number of people it can slowly progress over many years. Finding it early is the whole point
• Peptic ulcers — sores on the lining of your stomach or the very top of your small intestine. These can cause significant pain and, if untreated, can bleed
• Helicobacter pylori infection — a very common stomach bacterium that can cause ulcers and inflammation. It is identified through tiny biopsies taken during the procedure, and it is completely treatable with a short course of antibiotics
• Bleeding from the upper digestive tract — if the source of bleeding is found during the gastroscopy, it can often be treated on the spot using tiny clips, a small injection, or heat — without needing separate surgery
• Narrowing of the oesophagus (called a stricture) — where the swallowing tube has become tight, making it harder to swallow food. In many cases this can be gently stretched (dilated) during the same procedure
• Gastric polyps — small growths on the lining of the stomach. These can be assessed visually and, if needed, removed or biopsied during the same examination

Biopsies

If Mr Nguyen sees anything during the examination that needs closer analysis, he can take small tissue samples — called biopsies — through the camera during the same procedure. You will not feel this at all; it is completely painless under sedation. The samples are sent to a laboratory where a pathologist examines the cells under a microscope.

Biopsies are taken routinely in certain situations — for example, to test for Helicobacter pylori infection, or to get a clearer picture of any area of the lining that looks a little unusual. It does not mean anything serious has been found; it simply means Mr Nguyen wants to be thorough. Before you go home, he will talk you through what he saw and give you a written endoscopy report to take away — a copy is also sent directly to your referring doctor so everyone is on the same page.

Laboratory results (called histology) are usually back within two to four weeks. For most patients, Mr Nguyen will go through these results at a follow-up by phone or telehealth at no charge. If the results show anything that needs prompt attention, you will hear from us sooner — we will not leave you waiting unnecessarily. You are also always welcome to request a face-to-face review if you would prefer to discuss things in person.

Before the procedure

Risks & considerations

Gastroscopy is one of the safest endoscopic procedures performed, and serious complications are uncommon. The following list is meant to inform you, not alarm you — please read it with that in mind, and know that Mr Nguyen will talk through any risks specific to your situation before the procedure.

• Sore throat: Very common and usually mild — it often feels like the early stages of a cold. It settles on its own within 24 to 48 hours. Cool water and a throat lozenge can help in the meantime.
• Bloating and wind: The small amount of air used during the examination to open up the space can cause some temporary bloating or an urge to belch or pass wind. This is harmless and passes within a few hours. Most people barely notice it once they are home.
• Bleeding: There is a small risk of bleeding if a biopsy is taken or a treatment is performed (such as removing a polyp). In the vast majority of cases, any bleeding is minor and settles on its own. Significant bleeding requiring further treatment is uncommon.
• Perforation (a small tear in the wall of the oesophagus or stomach): This is rare, and more likely with therapeutic procedures — such as gently stretching a tight area — than with a straightforward diagnostic gastroscopy where Mr Nguyen is simply looking. If this did happen, it would be identified and treated promptly, and in very rare cases could require surgery.
• Sedation effects: The sedative medication used is very safe and routinely given. You may feel drowsy or a little unsteady for a few hours afterwards — this is why you will need a responsible adult to drive you home and stay with you for the rest of the day. Serious reactions to sedation are rare, and the team is trained and equipped to manage them if they ever occur.

If you have concerns about any of these risks — particularly in light of your own medical history — please raise them at your consultation. Mr Nguyen welcomes questions and will take the time to address anything that is on your mind.

Recovery

Recovery from a gastroscopy is quick — most people feel back to their normal selves by the following morning, and many feel well within a few hours. Here is what to expect, day by day.

In recovery (the first hour or so): Once the sedation starts to wear off — usually within 30 to 60 minutes of the procedure finishing — you will be helped to a comfortable recliner chair in the recovery area. The nursing team will offer you a drink and something light to eat. When they are satisfied that you are alert and steady on your feet, you are free to go home.

The rest of the day: You must have someone drive you home — you cannot drive yourself, take public transport alone, or make any important decisions for the remainder of that day. This applies even if you feel completely fine. The sedation affects your judgment and reflexes in ways you may not notice. Plan to rest at home, eat and drink normally, and take it easy.

Day 1 after: Most people feel entirely back to normal. Your throat may feel a little scratchy or tender — this is from the camera tube and is completely harmless. Sipping cool water or having a throat lozenge can soothe it. You can resume normal eating, activities, and medications.

When to contact us or seek help: Most people have no issues at all after going home. But please do get in touch with our rooms — or go directly to the emergency department — if you notice worsening pain in your chest, throat, or abdomen; new difficulty swallowing; fever; or any bleeding. These symptoms are uncommon but need prompt assessment.

Your follow-up: If biopsies were taken, Mr Nguyen will review those results with you within 2 to 6 weeks — by phone or telehealth at no charge for most patients. If anything in the results needs prompt attention, you will hear from us sooner, and an in-person appointment will be arranged. You are also always welcome to request a face-to-face review if you would prefer to discuss things in person.

Frequently asked questions

Related patient guides

These guides are written in plain language for patients and families. They cover topics that often come up around the time of a gastroscopy — feel free to read them before or after your appointment.