Upper endoscopy: what to expect before, during, and after

# Upper endoscopy: what to expect before, during, and after

Upper gastrointestinal endoscopy—gastroscopy or EGD—uses a thin flexible camera to examine the oesophagus, stomach, and first part of the small intestine. It can investigate swallowing difficulty, bleeding, anaemia, persistent vomiting, pain, reflux complications, or abnormal imaging, and can take biopsies or provide treatment during the same procedure.

Before the appointment

The stomach must be empty to see clearly and reduce aspiration risk. Follow the unit’s exact fasting times for solids and clear fluids. Report blood thinners, diabetes medicines, GLP-1 medicines, allergies, heart or lung disease, sleep apnoea, loose teeth, and previous sedation problems. Do not independently stop essential medication. Arrange an escort when sedation is planned.

During the procedure

A throat spray, intravenous sedation, or both may be offered depending on the unit and patient. Sedation aims for comfort and relaxation; it is not always a full general anaesthetic. You usually lie on your side with oxygen and monitoring. The scope does not block breathing. Air or carbon dioxide gently opens the upper gut, and the examination often takes only several minutes unless treatment is needed.

Biopsies and safety

Tiny biopsies are painless and may be taken even when the lining looks normal—for example, to assess coeliac disease or inflammation. Therapeutic endoscopy can stop bleeding, dilate a narrowing, or remove selected lesions. Endoscopy is generally safe, but reactions to sedation, bleeding, aspiration, infection, dental injury, or perforation can occur; risk depends on health and the planned intervention.

Recovery and results

A sore throat, mild bloating, or drowsiness can occur briefly. After sedation, an adult should take you home; do not drive, drink alcohol, operate machinery, sign legal papers, or make important decisions for the advised period. The endoscopist may explain visual findings immediately, while biopsy results take longer. Make sure you know how and when final results will reach you.

When gastroscopy answers the question

Upper endoscopy can investigate food sticking, painful swallowing, upper gastrointestinal bleeding, persistent vomiting, unexplained iron-deficiency anaemia, suspected coeliac disease, ulcer symptoms, abnormal imaging, or reflux with warning features. It is also used to monitor selected Barrett’s oesophagus or precancerous stomach conditions and to treat bleeding or narrowing. It is not automatically the best first test for every episode of indigestion. Age, H. pylori status, medicine use, alarm features, and response to initial care help determine whether endoscopy, non-invasive testing, imaging, or observation is most appropriate.

Fasting and medicine planning

The endoscopy unit gives exact cut-offs, commonly requiring no solid food for at least six hours and allowing clear fluids until a shorter interval before sedation, but local anaesthesia policy takes precedence. Food retained in the stomach obscures the view and can enter the lungs. Patients should identify anticoagulants, antiplatelet drugs, insulin, other diabetes medicines, GLP-1 therapies, iron, allergies, sleep apnoea, implanted devices, and loose teeth. Diagnostic biopsy and therapeutic procedures have different bleeding risks, so medication changes must come from the responsible clinical team.

What happens inside the room

After identity, consent, and safety checks, staff place a mouth guard and monitoring for pulse, oxygen, and blood pressure. Throat spray numbs gag sensation; conscious sedation can make the patient relaxed and drowsy while still breathing independently, and deeper anaesthesia is reserved for selected circumstances. The flexible scope passes over the tongue into the oesophagus—not the windpipe—while suction removes saliva. The endoscopist examines the oesophagus, stomach, and duodenum, gently adds gas for visibility, photographs findings, and performs planned samples or treatment.

Biopsy results, recovery, and rare complications

A biopsy is only a few millimetres and cannot be felt from inside the stomach. It may test for H. pylori, coeliac disease, inflammation, Barrett’s change, or an abnormal area; taking one does not mean cancer is expected. Throat discomfort and bloating usually settle quickly. Serious complications are uncommon but include aspiration, sedation reaction, bleeding, dental damage, infection, and perforation, with higher risk during dilation or treatment. Severe chest or abdominal pain, breathlessness, fever, vomiting blood, black stool, confusion, or persistent difficulty swallowing after discharge needs urgent contact.

Myths and facts

The scope prevents breathing

It passes through the oesophagus, not the windpipe.

A biopsy means cancer is suspected

Biopsies routinely assess many benign conditions.

A normal appearance ends the investigation

Microscopy or another test may still answer the clinical question.

When to see a doctor

Before the test, tell the unit about a new chest infection, worsening breathlessness, inability to fast, pregnancy, a medicine error, or lack of an escort when sedation is planned; the safest response may be to adjust or postpone the procedure. After discharge, mild throat discomfort and temporary bloating are common. Severe chest, neck, or abdominal pain, fever, breathlessness, repeated vomiting, vomiting blood, black stool, fainting, confusion, or difficulty swallowing that is getting worse is not routine recovery. Contact the endoscopy service or emergency care immediately, especially after dilation or another therapeutic intervention. Keep the discharge instructions beside you during the first night.

Practical checklist

• Confirm fasting times and which medicines to take.
• Bring a complete medicine list and relevant reports.
• Arrange an adult escort if receiving sedation.
• Seek urgent help for severe chest or abdominal pain, breathlessness, fever, vomiting blood, or black stool afterward.

A next step

You can book a consultation to discuss your questions.

Fixed medical disclaimer: This content is for general education and does not replace individual diagnosis or treatment by a qualified clinician. In an emergency, contact local emergency services immediately.

References

• NIDDK — Upper GI Endoscopy
• NHS — Gastroscopy
• ASGE — Understanding Upper Endoscopy