Overview
Upper endoscopy (gastroscopy) is a procedure in which a doctor passes a thin, flexible tube with a tiny camera at its tip through the mouth to directly examine the inside of the oesophagus (the food pipe), stomach, and the first part of the small intestine (the duodenum).
The camera sends live images to a screen so the doctor can look for abnormalities such as inflammation (redness and irritation), ulcers (open sores), or growths. If something unusual is seen, the doctor can pass small tools through the same tube to take a biopsy (a tiny tissue sample) for laboratory testing, or to treat a problem such as a bleeding vessel, all without making any cut in the skin.
Medical Condition
Doctors recommend upper endoscopy when they need a clear, direct view of the upper digestive tract to find the cause of symptoms or to confirm a diagnosis that other tests have suggested. It is also used during certain treatments that can be performed through the endoscope itself.
- Persistent heartburn or acid reflux (stomach acid rising into the food pipe) that does not improve with medication
- Difficulty or pain when swallowing
- Unexplained nausea, vomiting, or upper abdominal pain
- Vomiting blood or passing very dark, tar-like stools, which may indicate bleeding in the upper digestive tract
- Suspected peptic ulcer (an open sore in the stomach or duodenum)
- Suspected gastritis (inflammation of the stomach lining), including checking for Helicobacter pylori (a type of bacteria that can cause ulcers)
- Monitoring of Barrett's oesophagus (a condition where the lining of the food pipe changes and carries a small cancer risk)
- Investigation of unexplained weight loss or anaemia (low red blood cell count) linked to the digestive tract
- Removal of a foreign object accidentally swallowed
- Treatment of bleeding from the upper digestive tract using tools passed through the endoscope
Upper endoscopy is generally not performed in certain situations. Your doctor will assess each case individually.
- Suspected perforation (a hole or tear) in the digestive tract
- Severe, unstable heart or lung conditions that make sedation unsafe
- A severely narrowed oesophagus that the tube cannot safely pass through
- Patients who cannot cooperate with the procedure and for whom sedation carries too high a risk
Risks & Complications
Upper endoscopy is considered a low-risk procedure, and for most people it passes without any complication; however, as with any medical procedure, some risks exist and are worth understanding.
- Sore throat or mild discomfort in the throat after the tube is removed — this usually settles within a day or two
- Bloating or a gassy feeling from air that was introduced into the digestive tract during the procedure
- Nausea or drowsiness from the sedative (medication given to help you relax) — this usually wears off within a few hours
- Small risk of bleeding at a biopsy site — in most cases this stops on its own
- Reaction to the sedative medication, such as a drop in blood pressure or breathing changes — medical staff monitor for this throughout the procedure
- Aspiration (accidentally inhaling a small amount of stomach contents into the lungs) — uncommon and less likely when fasting instructions are followed
- Perforation (a small tear in the wall of the oesophagus, stomach, or duodenum) — this is rare but is the most serious possible complication and may require further treatment
- Infection — very uncommon with standard endoscopy when equipment is properly sterilised
Preparation & Procedure
Good preparation helps the doctor see the upper digestive tract clearly and keeps the procedure as safe as possible. Your medical team will give you specific instructions, but the following guidance covers what is typically expected.
Fasting is essential. Most hospitals ask patients to have nothing to eat or drink — including water — for at least six to eight hours before the procedure. This empties the stomach so the camera has a clear view and reduces the risk of inhaling stomach contents. Your team will confirm the exact fasting window.
Medication and lifestyle adjustments are usually discussed at a pre-procedure consultation. Patients taking blood thinners, aspirin, or iron supplements are often asked to pause these for a period beforehand, under their doctor's guidance. Smoking and alcohol are generally advised against in the days before the procedure, as both can affect the stomach lining. If you take medication for diabetes, your team will advise on any adjustments needed for the fasting period. Always inform the team of all medications, supplements, and any known allergies.
Tests run before the procedure may include a blood test to check for anaemia or clotting ability, and sometimes a review of previous imaging such as an ultrasound (USG) or CT scan. The doctor will also review your medical history and ask about previous procedures or surgeries on the digestive tract.
On the day of the procedure, the typical sequence of steps is as follows:
- Arrival and registration: the patient checks in and nursing staff confirm identity, fasting status, and allergies
- Consent: the doctor explains the procedure and the patient signs a consent form
- Preparation room: the patient changes into a hospital gown and an intravenous (IV) line is placed in a vein in the arm for giving fluids and sedation
- Throat spray: a local anaesthetic (numbing) spray is applied to the back of the throat to reduce the gag reflex
- Sedation: a sedative is given through the IV line — most patients feel drowsy and relaxed but remain conscious; in some hospitals, full sedation (general anaesthesia) may be offered
- Positioning: the patient lies on their left side on a procedure table
- Insertion of the endoscope: the doctor gently guides the tube through the mouth, down the throat, and into the oesophagus, stomach, and duodenum while the patient breathes normally
- Examination: the doctor inspects the lining of each area on the screen; biopsies or small treatments may be performed at this point
- Removal: once the examination is complete, the tube is slowly withdrawn
- Recovery: the patient is moved to a recovery area to be monitored until the sedative wears off
The examination itself usually takes between five and twenty minutes, though this can vary depending on what the doctor finds and whether any additional procedures are needed. Including preparation and recovery, patients should plan for a stay of several hours at the facility.
Aftercare
After the procedure, patients are moved to a recovery area where nursing staff monitor heart rate, blood pressure, and oxygen levels until the sedative has worn off. Most people feel well enough to go home within one to two hours, but because sedation affects coordination and judgement, patients must have a responsible adult accompany them home and should not drive or operate machinery for the rest of the day.
- Eating and drinking: the throat numbness from the local spray wears off within about an hour; once this has passed and the team gives the go-ahead, most patients can drink and eat lightly — your team will confirm when it is safe to start
- Sore throat: mild throat discomfort is common for a day or two and usually settles on its own; cold fluids or throat lozenges may help ease it
- Bloating: any gassy feeling from the procedure typically passes within a few hours as the introduced air is absorbed or passed naturally
- Activity: most patients can return to normal daily activities the following day; strenuous exercise is usually avoided for the remainder of the day of the procedure
- Driving and decisions: do not drive, sign legal documents, or make important decisions for at least 24 hours after sedation
- Biopsy results: if tissue samples were taken, results usually come back within a few days to two weeks, depending on the laboratory; your doctor will arrange a follow-up appointment to discuss findings
- Warning signs to report promptly: fever, increasing throat or chest pain, difficulty swallowing that worsens rather than improves, vomiting blood, or very dark stools — seek medical attention immediately if any of these occur
- Medications: your doctor will advise whether to restart any medications that were paused before the procedure, and when
- Follow-up: a follow-up consultation is usually scheduled to review results and, if needed, to plan any further treatment or surveillance
Frequently Asked Questions
Does an upper endoscopy hurt?
Most people feel uncomfortable rather than painful during the procedure, often describing a feeling of pressure or fullness in the throat and stomach. You will usually be given a sedative — medication to make you drowsy and relaxed — so many patients have little or no memory of it afterwards. A numbing spray may also be applied to the back of your throat to reduce the gag reflex.
How do I prepare for a gastroscopy — do I need to fast?
Yes, you need to have an empty stomach before a gastroscopy, so doctors typically ask you to stop eating and drinking for at least six to eight hours beforehand. This is important because food or liquid in the stomach can block the doctor's view and raise the risk of accidentally inhaling stomach contents. Your doctor will give you specific instructions, including guidance on whether to take your regular medications on the morning of the procedure.
How long does an upper endoscopy take?
The procedure itself usually takes between five and twenty minutes, though the time can vary depending on whether the doctor needs to take a small tissue sample — called a biopsy — or carry out any minor treatment during the same session. You should also plan for extra time before and after: preparation, sedation, and recovery in the clinic typically add one to two hours to your overall visit.
When will I get my gastroscopy results?
What the doctor sees through the camera — such as redness, ulcers, or unusual tissue — is usually discussed with you on the same day. If a biopsy was taken, the tissue sample is sent to a laboratory for analysis, and those detailed results commonly take a few days to about two weeks to come back, depending on what is being tested.
This page is general information, not a substitute for medical advice. Every case is different — your doctor decides what is right for you. Contact our team to be matched with an appropriate specialist.
