The procedures
- Gastroscopy (upper endoscopy): the camera passes through the mouth to examine the oesophagus (food pipe), stomach and first part of the small bowel.
- Colonoscopy: the camera passes through the back passage to examine the large bowel. Polyps can often be removed at the same time.
- More complex procedures, such as ERCP (to treat blockages of the bile or pancreatic ducts), endoscopic ultrasound, stretching narrowings, or removing larger polyps.
Many people have a gastroscopy and colonoscopy together during the same session.
The role of your specialist anaesthetist
While your gastroenterologist or surgeon performs the procedure, I give and adjust the sedation or anaesthetic, keep your breathing safe, and monitor you closely throughout. Having an anaesthetist dedicated to this role means the person doing the procedure can concentrate on it entirely.
Sedation or general anaesthesia
Most gastroscopies and colonoscopies are done under sedation. Medication is given through a drip in your hand or arm. You breathe on your own, and most people drift into a light sleep and remember little or nothing of the procedure. The depth of sedation can be adjusted continuously to keep you comfortable and safe.
General anaesthesia, sometimes with a breathing tube, may be appropriate for longer or more complex procedures such as some ERCPs, when there is a high risk of stomach contents entering the lungs, or for some people with significant medical conditions. Some people prefer to have little or no sedation, and this can also be discussed.
The right choice depends on your procedure and your health. Not every approach suits every patient, and I will talk with you about what I recommend and why.
Bowel preparation and fasting
Before a colonoscopy, the bowel needs to be completely empty so that it can be seen clearly. You will be given a bowel preparation (a strong laxative) with specific instructions about diet and timing. Before any endoscopy, you will also be asked to fast for a period. These instructions vary between procedures and facilities, and they are given to you individually. Please follow the instructions you receive, and contact the facility if anything is unclear.
Bowel preparation can make you lose fluid, so drinking the allowed clear fluids is important. If you have diabetes, kidney problems or heart failure, please seek individual advice early. Some medicines need particular attention before endoscopy, including blood thinners, iron tablets, diabetes medicines, and GLP-1 and other weight-loss medicines, which can slow stomach emptying. Please do not stop or change any prescribed medication unless your anaesthetist, gastroenterologist, GP or prescribing doctor has advised you. See Medications Before Anaesthesia and Preparing for Your Procedure.
What happens during the procedure
I will check your details, review your health and answer any final questions. A small cannula is placed in your hand or arm, and you will lie on your side. Oxygen is given through a soft tube under your nose or a mouthpiece. Throughout the procedure your heart rhythm, blood pressure and oxygen levels are monitored, and your breathing is watched closely, often including measurement of the carbon dioxide you breathe out. A gastroscopy usually takes a few minutes and a colonoscopy usually takes somewhat longer, though times vary.
Recovery and discharge arrangements
You will wake in the recovery area, where nurses continue to monitor you. Some bloating or cramping from air used during the procedure is common and settles quickly. A mildly sore throat after gastroscopy is also common. Most people go home within an hour or two. Your gastroenterologist will usually explain the findings before you leave, but because sedation can affect memory, it helps to have someone with you, and you will be given written information.
Contact the facility or your doctor if you develop severe abdominal pain, a fever, vomiting, or more than a small amount of bleeding. In an emergency, call 000. See also Recovery & Aftercare.
Relevant anaesthetic risks and precautions
Sedation for endoscopy is very commonly given and serious problems are uncommon. The most frequent effects are drowsiness, and a temporary drop in blood pressure or oxygen level, which are detected by monitoring and treated promptly. Breathing can slow or the airway can partly close under deeper sedation; this is why an anaesthetist is present and airway equipment is always ready. Inhaling stomach contents is rare, and fasting reduces this risk. Allergic reactions to sedation medicines are rare.
Your gastroenterologist will explain the risks of the procedure itself, such as bleeding or, rarely, a tear in the bowel wall. See Anaesthetic Safety & Risks.
Links to additional patient resources
- Preparing for Your Procedure
- Understanding Your Anaesthetic & Informed Consent
- Medications Before Anaesthesia
- Recovery & Aftercare
- Anaesthesia for endoscopy, Australian and New Zealand College of Anaesthetists (ANZCA)
- Gastroenterological Society of Australia (GESA), including patient resources