Upper GI Endoscopy (Gastroscopy)

The upper digestive tract runs from the throat through the oesophagus into the stomach and on to the duodenum, where bile and pancreatic juices join food. Upper GI endoscopy, also called oesophagogastroduodenoscopy or OGD, examines these three areas from the inside with an endoscope: a flexible tube slightly thinner than a little finger, carrying a light, a camera and a working channel. The images appear on a screen in high definition, and many systems can enhance the view with special light filters that make subtle changes in the lining easier to see. Through the channel the specialist can take biopsies, test for Helicobacter pylori, a stomach infection that causes ulcers, remove small polyps, stop bleeding, band swollen veins or stretch a narrowing. A gastroscopy therefore often both explains the symptoms and starts the treatment. In some units a thinner scope can be passed through the nose instead of the mouth.

Gastroscopy is recommended when symptoms point to the upper gut and simple treatment has not settled them, or when there are warning signs. Common reasons are heartburn or acid reflux that persists despite medicine, indigestion, pain or discomfort in the upper abdomen, nausea and repeated vomiting, and difficulty or pain when swallowing. Warning signs that make an endoscopy more urgent include vomiting blood, black tarry stools, iron-deficiency anaemia, unexplained weight loss and food sticking in the throat or chest. Gastroscopy is also used to confirm coeliac disease with duodenal biopsies, to check the healing of a stomach ulcer, to look for varices in liver disease and to monitor Barrett's oesophagus, a change in the lining caused by long-term reflux. It is often part of the assessment before anti-reflux or weight-loss surgery. When the lower bowel also needs examining, it can be combined with a colonoscopy in the same visit.

You fast beforehand and remove dentures or glasses. Depending on your preference and the plan, the throat is numbed with a local anaesthetic spray, a sedative is given through a small cannula in your arm, or both; some units offer light anaesthesia given by an anaesthesia team. You lie on your left side with a plastic mouthguard between your teeth to protect them and the scope. The specialist passes the endoscope over the tongue and asks you to swallow as it enters the oesophagus; it does not block your breathing. A little air is used to open the stomach so the lining can be seen, which may make you feel full or want to burp. The whole upper tract is inspected, biopsies are taken if needed, and the scope is withdrawn. A diagnostic examination usually takes about 5 to 15 minutes, and you then rest until any sedation wears off before the findings are explained.

Gastroscopy suits almost anyone who needs the upper gut examined, including older people and those with other illnesses, with sedation adjusted to heart and lung health. Preparation is simple compared with a colonoscopy. You usually stop eating about six hours before the test and stop clear fluids about two hours before, although the unit gives its own timing. Some acid-suppressing medicines are paused for up to two weeks before a test aimed at Helicobacter pylori, on medical advice. Blood thinners, diabetes medicines and weight-loss injections that slow stomach emptying need specific instructions, so share a full medicine list in advance. If you have sedation, a companion must take you back to your accommodation, and you should not drive for the rest of the day. International patients can send symptoms, earlier reports and a medicine list ahead, so the team can confirm the plan before travel.

Recovery after a diagnostic gastroscopy is short. With throat spray alone you can leave almost straight away; after sedation you rest for about an hour and need someone to accompany you. Once the numbness wears off you can drink and then eat, usually starting with something soft. A mildly sore throat, bloating or burping is common for up to a day. Severe chest or abdominal pain, vomiting blood, black stools, fever or difficulty breathing after the test need urgent medical attention. If treatment was carried out, such as dilation of a narrowing, banding of varices or removal of a larger polyp, the team may advise a softer diet, an overnight stay or a longer interval before flying. For a simple examination many visitors plan one or two days in total and fly the next day. Agree beforehand how biopsy results will reach you and your home doctor.

Upper GI endoscopy is a very common hospital procedure and is generally safe. The usual effects are minor: a sore throat, bloating and drowsiness from sedation. Uncommon risks include a reaction to sedation affecting breathing or blood pressure, bleeding after a biopsy or treatment, inhaling stomach contents into the lungs, and a perforation, a small tear in the oesophagus or stomach, which is rare and more likely when a narrowing is stretched or a lesion removed. Teams reduce these risks with fasting, monitoring and careful technique, and the mouthguard protects your teeth. Gastroscopy shows the lining clearly, but a small early lesion can occasionally be missed, so biopsies are taken from anything unclear. The result guides the next step, for example acid suppression, Helicobacter pylori treatment, surveillance of Barrett's oesophagus, endoscopic treatment or referral for surgery.