Upper GI endoscopy

What it is

Upper gastrointestinal endoscopy, or oesophagogastroduodenoscopy (OGD, EGD), uses a flexible video endoscope passed through the mouth to inspect the oesophagus, stomach and duodenum, usually as far as the second part of the duodenum. It is both diagnostic and therapeutic: biopsies can be taken (for Helicobacter pylori, coeliac disease, Barrett oesophagus or a suspected cancer), and bleeding ulcers can be treated, varices banded, strictures dilated, foreign bodies removed and feeding tubes placed. The test is done by an endoscopist, not by the referring doctor, but the referring doctor decides whether it is needed and how urgently, explains it, prepares the patient and acts on the report. It is usually done as a day case with a local anaesthetic throat spray, conscious sedation or both, with the patient lying on the left side; a mouth guard protects the scope. A routine diagnostic test takes only a few minutes. In upper GI bleeding, resuscitation comes first, a risk score (Glasgow-Blatchford) helps decide who needs early endoscopy, and the endoscopist describes the ulcer with the Forrest classification, which predicts the risk of rebleeding and guides endoscopic treatment.

Indications

• Dysphagia, odynophagia, or dyspepsia with alarm features or in an older patient with new symptoms.
• Upper GI bleeding (haematemesis, melaena) and unexplained iron-deficiency anaemia, with colonoscopy as needed.
• Suspected coeliac disease with positive serology, when duodenal biopsies confirm the diagnosis.
• Surveillance: Barrett oesophagus, and screening for oesophageal varices in cirrhosis.
• Therapy: haemostasis, variceal banding, dilation or stenting of strictures, foreign body or food bolus removal, feeding tube placement.

Contraindications

• Suspected or known perforation of the oesophagus or stomach (absolute).
• Haemodynamic instability or hypoxaemia that has not been corrected: resuscitate first, protect the airway if needed.
• A patient who refuses or cannot cooperate, unless done under anaesthesia with a secured airway.
• Recent myocardial infarction, severe cardiorespiratory disease or recent upper GI surgery: weigh the benefit with the team.
• Anticoagulants and antiplatelets: not a bar to a diagnostic test, but plan them for therapeutic procedures.

Preparation and what happens

1. Explain the test and get informed consent, including the risk of bleeding or perforation — the patient decides with full information.
2. Ask the patient to fast for food and drink as the local protocol says — an empty stomach is safer and gives a clear view.
3. Review anticoagulants, antiplatelets and diabetes treatment with the guideline — they may need to be held or adjusted.
4. Ask about allergies, loose teeth, dentures and previous sedation — they affect safety and the plan for the airway.
5. Arrange an escort home if sedation is planned — judgement and reflexes stay impaired for the rest of the day.
6. On the day: cannula, monitoring of oxygen, pulse and blood pressure, oxygen given if sedated — sedation can depress breathing.
7. Throat spray and/or sedation, left lateral position, mouth guard — this eases passage of the scope and protects it.
8. The scope is passed under vision, the lumen is inspected, air is insufflated and biopsies are taken — insufflation opens the folds.
9. Recovery: observe until awake, nothing by mouth until the throat spray wears off — the swallow is numb and aspiration is possible.

Forrest classification of peptic ulcers at endoscopy

Risks and complications

• Sore throat, bloating and belching from the air: common and short-lived.
• Cardiopulmonary events from sedation (hypoxaemia, hypotension, arrhythmia): the most frequent serious problems.
• Aspiration, particularly in upper GI bleeding or with a full stomach.
• Bleeding after biopsy or therapy, more likely in patients on antithrombotic drugs.
• Perforation: rare in diagnostic tests, more likely after dilation or removal of a lesion; neck, chest or abdominal pain afterwards is a warning.

Next step

• Read the report: findings, biopsies taken, therapy given and the endoscopist's plan (for example a repeat test or a treatment).
• Chase the histology (H. pylori, coeliac disease, dysplasia, cancer) and act on it: eradication, diet, surveillance or referral.
• After a bleeding ulcer: continue acid suppression as advised, treat H. pylori, review NSAIDs and the plan for antithrombotics.
• Severe chest, neck or abdominal pain, fever, surgical emphysema or new bleeding after the test: call a senior; imaging looks for perforation.
• Give written aftercare: when to eat, no driving or legal decisions on the day of sedation, and who to call.

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Elsewhere in DurgiPedia

• Upper and lower gastrointestinal bleeding
• Informed consent: elements and how to obtain it
• Dysphagia and aspiration precautions

Connections

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Educational content; it does not replace supervised hands-on training, your institution's protocols or a prescriber's order. A procedure is learnt with a teacher and done only once you are trained to do it.

Sources: Esophagogastroduodenoscopy (EGD) (StatPearls (NCBI Bookshelf), 2026).

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