An upper gastrointestinal (GI) endoscopy, also known as a gastroscopy, is a procedure that allows doctors to look directly at your gullet (oesophagus), stomach and the first part of the small bowel (duodenum). The procedure can be uncomfortable but is not usually painful. It can be carried out using a local anaesthetic throat spray, sedation, or a combination of both.
There are many reasons why an upper GI endoscopy may be recommended, including:
- Indigestion
- Anaemia
- Unexplained weight loss
- Vomiting
- Passing black bowel motions
- Vomiting blood
- Difficulty swallowing
The procedure helps identify the cause of your symptoms, guide treatment, and decide whether further investigations are needed.
What happens during the procedure?
The procedure itself usually takes around 5 minutes, but you should allow up to 2 hours in total for your hospital visit.
During the endoscopy:
- A thin, flexible tube (gastroscope) is passed through your mouth into your stomach
- A small amount of air is used to improve visibility
- Tissue samples (biopsies) may be taken painlessly if required
- Photographs may be taken for your medical records
You will be monitored throughout the procedure by trained staff.
Preparing for your gastroscopy
To ensure clear views, your stomach must be empty.
Eating and drinking
- Do not eat for at least 6 hours before your procedure
- You may sip water up to 2 hours before your appointment
Morning appointment
- Do not eat after midnight
Afternoon appointment
- You may have a light breakfast (for example toast and tea or coffee) no later than 7:30am
If these instructions are not followed, your procedure may be delayed or cancelled.
Medications
Most medications can be taken as normal unless stated in your appointment letter.
Diabetic patients should not take insulin or tablets while fasting but should bring them to the appointment. Please contact the Endoscopy Unit or Diabetes Department for advice.
Throat spray or sedation
Throat spray
A local anaesthetic spray numbs your throat.
Benefits:
- You remain fully awake
- You can resume normal activities shortly after
You must not eat or drink for 90 minutes after the procedure or until sensation returns.
Sedation
Sedation is given through a vein in your arm. You will feel relaxed and drowsy but remain conscious.
If you choose sedation:
- You will need someone to take you home
- Someone must stay with you overnight
- For 24 hours you must not:
- Drive
- Drink alcohol
- Operate machinery
- Sign legal documents
On the day of your appointment
- Report to the Endoscopy Unit reception
- A nurse will check your medical history and explain the procedure
- Your observations (blood pressure, pulse, oxygen levels) will be recorded
- You will be asked to sign a consent form
Friends or family will be asked to wait while you are taken into the procedure area.
During the procedure
- Dentures will be removed
- You will lie on your left side
- A mouth guard may be used to protect your teeth
- Oxygen and monitoring equipment may be applied
You may gag or cough briefly, but your breathing will not be affected.
Risks and complications
Gastroscopy is generally safe, but complications can occur.
Main risks include:
- Damage to teeth or dental work
- Perforation or tearing of the gullet or stomach lining (approximately 1 in 2000 cases)
- Bleeding
Sedation risks
Sedation can rarely affect breathing, heart rate or blood pressure. You will be closely monitored throughout.
Emergency or therapeutic procedures
Risks are higher for emergency or treatment procedures, such as stretching a narrowed gullet or stopping internal bleeding.
After the procedure
- You will be monitored in recovery
- You may be offered a drink and biscuit (unless you had throat spray)
- Your throat may feel sore and you may feel bloated – this usually settles quickly
A report will be sent to your GP and the doctor responsible for your care.
Sedation effects can last up to 24 hours, so rest is advised.