During gastroscopy an operator – a doctor – looks into the upper part of one’s gut or the upper gastrointestinal tract. The upper gut consists of the gullet (esophagus), the stomach and the first part of the gut (small intestine) known as the duodenum. Since the operator uses an endoscope to look inside the gut, the test is sometimes termed as endoscopy.

An endoscope is a thin, flexible telescope. It is about as thick as a little finger. The endoscope is passed through the mouth, into the esophagus and down towards the stomach and duodenum. The tip of the endoscope contains a light and a tiny video camera so the operator can see inside your gut. The endoscope also has a side channel down which various instruments can pass. These can be manipulated by the operator. For example, the operator may take a small sample (biopsy) from the inside lining of the stomach by using a thin ‘grabbing’ instrument which is passed down a side channel.

A gastroscopy may be advised if one has symptoms such as:

• Pains in the upper tummy (abdomen).
• Repeated (recurring) indigestion.
• Recurring heartburn.
• Difficulty swallowing.
• Repeatedly being sick (vomiting).
• Stomach Cancer
• Oesophageal cancer
• Inflammation of the gullet (Oesophagus) called Oesophagitis – Redness in the esophagus (Usually affects lower part of food pipe (Oesophagus)
• Stomach & Duodenal Ulcer: An ulcer looks like a small, red crater on the inside lining of the stomach or on the first part of the gut (small intestine) known as the duodenum.
• Inflammation of the duodenum (duodenitis) and inflammation of the stomach (gastritis).
• Various other rare conditions.

Gastroscopy is usually done as an outpatient ‘day case’. It is a routine test which is commonly done. The operator may numb the back of one’s throat by spraying on some local anesthetic, or give one an anesthetic lozenge to suck. One may be given a sedative to help relax. This is usually given by an injection into a vein in the back of one’s hand. The sedative can make one drowsy but it does not put one to sleep. It is not a general anesthetic.

One lies on one side on a couch. One is then asked to put a plastic mouth guard between the teeth. This protects one’s teeth and stops one from biting the endoscope. The operator will then ask to swallow the first section of the endoscope. Modern endoscopes are quite thin and easy to swallow. The operator then gently pushes it further down one’s gullet (esophagus) and into one’s stomach and the first part of the gut (small intestine) known as duodenum. The video camera at the tip of the endoscope sends pictures to a screen. The operator watches the screen for abnormalities of the esophagus, stomach and duodenum. Air is passed down a channel in the endoscope into the stomach to make the stomach lining easier to see. This may cause you to feel full and want to belch.

The operator may take one or more small samples (biopsies) of parts of the inside lining of the gut – depending on why the test is done and what they see. This is painless. The biopsy samples are sent to the laboratory for testing and to look at under the microscope. The endoscope is then gently pulled out.

A gastroscopy does not usually hurt but it can be a little uncomfortable, particularly when one first swallows the endoscope.

Advice about medication which may need to be stopped before that test will be given.

If a sedative is given, one will need somebody to accompany home.

Most people are ready to go home after resting for half an hour or so.

If one has had a sedative – one may take a bit longer to be ready to go home. The sedative will normally make one feel quite pleasant and relaxed. However, one should not drive, operate machinery or drink alcohol for 24 hours after having the sedative. One will need somebody to accompany home and to stay with for 24 hours until the effects have fully worn off.

The operator writes a report and sends it to the doctor who requested the gastroscopy. The result from any sample (biopsy) may take a few days.

Gastroscopy is a good test for seeing abnormalities in the upper gut. However, it is not fool proof. For example, gastroscopy may not detect a small number of cases of early ulcers or early cancer. Sometimes a repeat gastroscopy may be advised if symptoms persist or get worse, even if a previous gastroscopy was reported as normal.

Most gastroscopies are done without any problem. Some people have a mildly sore throat for a day or so afterwards. One may feel tired or sleepy for several hours if one is given a sedative.

Occasionally, the endoscope causes some damage to the gut. This may cause bleeding, infection and (rarely) a hole (perforation). If any of the following occur within 48 hours after a gastroscopy, a doctor should be consulted immediately:

• Bringing up (vomiting) blood.
• Raised temperature (fever).
• Tummy (abdominal) pain. (In particular, if it becomes gradually worse, and is different or more intense to any ‘usual’ indigestion pains or heartburn that you may have.)
• Difficulty breathing.

A small number of people have a heart attack or stroke during, or soon after, a gastroscopy. These tend to be older people who are already in poor health. These serious complications are rare in most people who are otherwise reasonably healthy.

There could be an allergic reaction to the sedative in some rare cases.