Explaining a Gastroscopy (Endoscopy) – OSCE Guide

This article provides a step-by-step guide to explaining a gastroscopy (endoscopy) in an OSCE, including information you will be expected to give and how to structure the consultation.
The terms gastroscopy, upper GI endoscopy, and oesophagogastrodudenoscopy (OGD) are often used interchangeably.
This guide will cover what a gastroscopy is, what the procedure involves and the risks of the procedure.
Download the explaining a gastroscopy PDF OSCE checklist, or use our interactive OSCE checklist.

Opening the consultation
Wash your hands and don PPE if appropriate.
Introduce yourself to the patient including your name and role.
Confirm the patient’s name and date of birth.
Explain the reason for the consultation: “I understand that you’re here to talk about having a gastroscopy, is this correct?”.
Due to the sensitive nature of the consultation, it’s important to establish a good rapport and open line of communication with the patient early in the consultation: “If you have any questions at any point, or if something is not clear, please feel free to interrupt and ask me.”
Make sure to check the patient’s understanding at regular intervals throughout the consultation and provide opportunities to ask questions (this is often referred to as ‘chunking and checking’).
Throughout the consultation, be receptive to the patient’s language and try only to use words and terminology they are comfortable with.
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Ideas, concerns, and expectations
A key component of history taking involves exploring a patient’s ideas, concerns, and expectations (often referred to as ICE) to gain insight into the patient’s thoughts about having a gastroscopy, what they are worried about and what they expect from the consultation. When discussing concerns, do so in a sensitive and honest manner.
It can be challenging to use the ICE structure in a way that sounds natural in your consultation, but we have provided several examples for each of the three areas below.

“What do you already know about having a gastroscopy?”


“Is there anything worrying you about having a gastroscopy?”


“What were you hoping we would cover today relating to having a gastroscopy?”
“Is there anything you especially wanted to focus on or discuss today?”
“What are you hoping to get out of this consultation?”

Patient history
Although the purpose of this station is to explain the procedure, it is a good idea to gather a quick, focused history early in the consultation.
This should include exploring the patient’s condition and reason for requiring a gastroscopy: “Just so we are on the same page, could you tell me a bit about why you need a gastroscopy?”
Understanding the indication for the procedure will allow you to tailor your explanation.

What is a gastroscopy?
Using patient-friendly language, explain that a gastroscopy or oesophagogastrodudenoscopy (OGD), is a procedure performed by an endoscopist (doctor or specialist nurse) allowing visualisation of the upper gastrointestinal tract. This includes the oesophagus, stomach and duodenum. 
An endoscope (long flexible tube with a camera) is passed into the patient’s mouth, down the oesophagus towards the stomach then the duodenum. The endoscope has a light source and camera. Samples or biopsies can be taken during the procedure.1,2,3,4,5
“A gastroscopy is a test to examine the upper part of your digestive tract. The upper part of your gut consists of your food pipe or oesophagus, the stomach and the first part of the small intestine, known as the duodenum. A long, thin, flexible tube with a camera (endoscope) is passed through your mouth, down the food pipe towards the stomach and duodenum. Images will be relayed to a video monitor so the operator can see inside your gut, and they may take some small samples of cells to be checked in a laboratory called a biopsy.”

Why is a gastroscopy performed?
A gastroscopy is a common procedure for diagnosing and monitoring diseases affecting the oesophagus, stomach and duodenum:8

Barrett’s oesophagus
Gastric or oesophageal cancer
Coeliac disease
Hiatus hernia
Oesophageal varicies

Indications for a gastroscopy include:2,3,4,6,7

Persistent dyspepsia (despite treatment)
Persistent nausea or vomiting
Haematemesis or malaena
Unexplained weight loss
Iron deficiency anaemia: to investigate for any upper gastrointestinal causes of bleeding
Upper abdominal mass

“Gastroscopy is a medical procedure used to diagnose and monitor certain conditions in the upper digestive tract. It’s often recommended when you have symptoms such as difficult or painful swallowing, persistent heartburn or indigestion that doesn’t go away with medication, nausea or vomiting, or bringing up blood or dark-coloured, sticky, tar-like stool. It can monitor conditions like gastroesophageal reflux disease (GORD) or diagnose precancerous or cancerous changes in the upper digestive tract.”

What are the alternatives to gastroscopy?
Gastroscopy is not appropriate for some patients. The main alternative is a Barium swallow or a ‘barium meal’.
A barium swallow is non-invasive and doesn’t require sedation. The patient drinks barium liquid, which coats the inside of the oesophagus and stomach. X-rays are taken to produce images of the upper GI tract.
This can show any motility problems in the oesophagus and identify growths or abnormal areas. However, gastroscopy is preferred for a detailed mucosa examination and biopsy or lesion removal.4,9
“If a gastroscopy is not possible or recommended for you, another option is a barium swallow. This test is less invasive and doesn’t involve sedation. You will be asked to drink a barium liquid, which will appear as bright white on X-rays. This will help us to see the outline of your oesophagus and stomach. Unlike gastroscopy, a barium swallow doesn’t allow a direct view of the walls of your gut or any samples (biopsies) to be taken. It is still a useful test to help us see any mobility problems in your food pipe (oesophagus) or detect any growths or abnormalities.”

Preparing for a gastroscopy
Patients should receive a letter inviting them to the procedure, informing them of when to stop eating and drinking and which medications to avoid (e.g. proton pump inhibitors).
Proton pump inhibitors (e.g. omeprazole, lansoprazole) are usually stopped two weeks before the procedure. However, these medications can be continued in some cases (e.g. severe symptoms or undergoing a follow-up gastroscopy to assess ulcer healing).1
Anticoagulants and anti-platelet agents may also need to be stopped before the procedure. However, this depends on several factors, including the indication for anticoagulation and the bleeding risk of the gastroscopy. 
Inform the patient that on the day of the procedure, they should not eat anything for six hours before, but clear fluids can be consumed up to two hours before. 10,11
“You will receive a letter in the post telling you when your appointment is. It is important you tell the clinic if you are taking medications, especially blood thinners, or have any allergies.”
“Acid-reducing medications are usually stopped two weeks before the test. This increases the detection of disease. This period without medication can cause a slight increase in symptoms, but this doesn’t cause any harm.”
“On the day, stop eating six hours before your appointment. You can still have clear fluids up until two hours before.”

What happens during the procedure?
On arrival
Explain to the patient that when they arrive, a nurse will talk them through the procedure and possible risks, and they will need to give their written consent. There is no need for the patient to change clothes before the procedure.
The patient can choose between a local anaesthetic throat spray or intravenous sedation:5,10,11

Throat spray: the mouth and back of the throat will be numbed, reducing the gag reflex and the sensation of the scope in the throat.
Intravenous sedation: will relax the patient, but they will remain awake during the procedure. The patient will need to have a cannula placed to administer the medication, and the patient will need to arrange for a responsible adult to take them home after the procedure and stay with them for 24 hours.

“Before you can have the procedure, you must give your written consent. This will confirm that you understand the risks and agree to proceed with the procedure.”
“Before the procedure, you will be offered a local anaesthetic throat spray or a sedative to make you more comfortable.”
“A local anaesthetic throat spray will make your throat and mouth feel numb, it will reduce the gag reflex and make the procedure easier and more comfortable.”
“If you have a sedative, you are awake, but it relaxes you and helps you to feel calm. This will be given through an intravenous needle in your arm. You shouldn’t drive for 24 hours after, so make sure you have someone to pick you up and can stay with you after the procedure until the effects have fully worn off.”
Gastroscopy procedure
A gastroscopy takes 10 to 30 minutes. The patient is taken to a room with the endoscopist and two nurses. They will be asked to lie on their left side on a couch. The patient may be given a plastic mouth guard to protect their teeth and stop them from biting the endoscope. A nurse will use suction to clear saliva or secretions from the patient’s mouth.
The operator will gently place the endoscope into the patient’s mouth through the mouthpiece and ask them to swallow the first part of the endoscope. The endoscopist will gently push it down further and into the oesophagus. Air will be passed down the endoscope to inflate the stomach. This gives better visualisation of the lining.
Reassure the patient that they can breathe and swallow during the procedure.
The scope will relay images to a video monitor. The operator may take pictures stored in the patient’s medical records. The operator may take some biopsies for testing. This is not painful.1,5,10
“For the gastroscopy, you will be taken to a room with the endoscopist and two nurses. One nurse to assist the doctor, and the other to look after you. You will be asked to lie on your left side on a couch. You will be given a small plastic mouthpiece to bite on. This will protect your teeth. A nurse will use a small suction tube to remove saliva produced during the procedure, like at the dentist.”
“The endoscopist will gently place the scope in your mouth, and you will be asked to swallow the scope. The endoscopist will advance the scope down your food pipe/oesophagus down into your stomach and the first part of your intestine/duodenum.”
“Air will be passed into your stomach; this makes the lining easier to see. This air is removed at the end of the test but can make you feel bloated and uncomfortable. While this is not painful and does not affect your ability to breathe or swallow, it may cause some discomfort.”
“During the procedure, images of your gut will be relayed to a video monitor. The operator may take pictures and take some small samples of tissue (biopsies) to be sent to the laboratory for further testing; this is not painful.”
“The whole procedure will take 10 to 30 minutes.”                             
What happens after the procedure
After the gastroscopy, the patient is moved to a recovery room and closely monitored until they are ready to go home.
If the patient had local anaesthetic throat spray, they can resume their normal activities, including driving, immediately after the procedure. However, patients should avoid eating or drinking for at least one hour after the test until the sensation in their throat has returned to normal.1
Patients who have had intravenous sedation will need a responsible adult to pick them up and stay with them for 24 hours. For the next 24 hours, patients should avoid driving, operating machinery, drinking alcohol or signing legal documents.
Before the patient is discharged, a doctor or nurse will explain any findings from the gastroscopy. Biopsy results may take up to eight to ten weeks.5, 11
“After the procedure, you will be taken to a recovery room, where the nurses will look after you until you are ready to go home.”
“If you have the anaesthetic throat spray, you can drive and continue your day as normal. You shouldn’t eat or drink for at least an hour after the procedure until the feeling in your throat returns to normal.”
“If you have sedation, it’s important to arrange for a responsible adult to pick you up and stay with you for 24 hours after the procedure until the effects have fully worn off. During the first 24 hours after the procedure, you should avoid driving, drinking alcohol, operating heavy machinery, or signing legal documents.”
“Before you leave the hospital, a nurse or doctor will explain the gastroscopy findings. Any samples taken will be sent to a laboratory and examined by a pathologist. These results can take eight to ten weeks.”  

What are the side effects and risks?
Common side effects of gastroscopy include:1,3,4

Gagging and retching: reassure the patient this is a natural response to the endoscope touching the back of their throat
Sore throat
Bloating or nausea immediately after
Abdominal pain
Minor bleeding when a biopsy is taken

Possible risks of a gastroscopy include:5

Damage to teeth or dental work
Aspiration pneumonia
Sedation: risk of allergic reaction or over-sedation leading to cardiopulmonary depression

“Gastroscopy is a very safe procedure, but there are potential risks and side effects that should be considered.”
“During the procedure, it is common to have a gagging or retching sensation as the scope touches the back of your throat. Afterwards, you may experience a sore throat, discomfort, bloating and belching due to the air passing through the scope.”
“In some cases, there may be minor bleeding from biopsies taken during the procedure.”
“The endoscope can damage your teeth. To reduce this risk, your teeth are protected with the mouth guard.”
“Having a gastroscopy can cause small food particles from your gut to fall into the lungs causing a chest infection. This is why your stomach needs to be empty before the procedure.”
“In rare cases, the endoscope can damage the gut. This may cause bleeding, infection and rarely a tear in the stomach lining or oesophagus. This is called a perforation and usually requires an operation to repair. Make sure to seek urgent medical advice if you experience vomiting blood, severe abdominal pain, difficulty breathing or fever after having a gastroscopy.”

Closing the consultation
Close the consultation by summarising what you have discussed. This allows you to emphasise the key points of the consultation.
Finally, thank the patient for their time and offer them a leaflet summarising the key information.
Dispose of PPE appropriately and wash your hands.

Dr Ian Beales 
Consultant in Gastroenterology
Clinical Reader in Gastroenterology and Therapeutics


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Guys and St Thomas NHS. Preparing for Gastroscopy. 2021. Available from: [LINK]
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