Upper Gastrointestinal Endoscopy 

What is an Upper GI Endoscopy (OGD)?

Upper GI endoscopy, also called OGD (oesophago-gastro-duodenoscopy), ‘gastroscopy’ or simply an ‘endoscopy’, is a test which allows the doctor to look directly at the lining of the oesophagus (the gullet), the stomach and around the first bend of the small intestine – the duodenum. In order to do the test, an endoscope is passed through your mouth into the stomach. The endoscope is a thin flexible tube (no larger than a finger) with a bright light and video camera at the end. The endoscopist gets a clear view of the lining of the stomach and can check whether or not any disease is present. Sometimes the endoscopist takes a biopsy – a sample of tissue for analysis under the microscope in the laboratory, the tissue is removed painlessly through the endoscope using tiny forceps. 

Bowel preparation

To allow a clear view, the stomach must be empty. You will therefore be asked not to have anything to eat or drink for at least six hours before the test. When you come to the department, a doctor or nurse will explain the test to you and will usually ask you to sign a consent form. This is to ensure that you understand the test and its implications. Please tell the doctor or nurse if you have had any allergies or bad reactions to drugs or other tests. They will also want to know about any previous endoscopy you have had. If you have any worries or questions at this stage don’t be afraid to ask, the staff will want you to be as relaxed as possible for the test and will not mind answering your queries. You may be asked to take off your shirt or jumper and to put on a hospital gown. It will also be necessary for you to remove any false teeth, they will be kept safely until after the examination. 

During the procedure

In the examination room you will be made comfortable on a bed, resting on your left side. A nurse will stay with you throughout the test. Some endoscopists may spray a local anaesthetic on the back of your throat. The endoscopist may also give you an injection into your arm to make you feel sleepy and relaxed, but many hospitals now find that the test can be performed without any sedation as the endoscopes have become much smaller and easier to swallow. To keep your mouth slightly open, a plastic mouthpiece will be put gently between your teeth. When the endoscopist passes the endoscope into your stomach it will not cause you any pain, nor will it interfere with your breathing at any time. It may take up to fifteen minutes to examine all the areas of the oesophagus, stomach and duodenum carefully. During this time, some air will be passed down the endoscope to distend the stomach and allow a clearer view. The air is sucked out at the end of the test. If you get a lot of saliva in your mouth, the nurse will clear it using a sucker. When the examination is finished, the endoscope is removed quickly and easily. 

After the procedure

You will be left to rest in the unit for at least thirty minutes. You will be given a drink but if you have had your throat numbed by a spray, you will have to wait until your swallowing reflex is back to normal – this usually takes no more than an hour. After this you can eat and drink normally. The back of your throat may feel sore for the rest of the day. You may also feel a little bloated if some of the air has remained in your stomach. Both these discomforts will pass and need no medication. 

Going home

If you are going home after the test it is essential that someone comes to pick you up. Once home, it is important to rest quietly for the remainder of the day. Sedation lasts longer than you think, so if you have been given an injection during the examination you should not:

  • drive a car
  • operate machinery
  • drink alcohol

The effects of the test and injection should have worn off by the next day, when most patients are able to resume normal activities.

When will I know the results?

In most cases the endoscopist will be able to tell you the results straight after the test or, if you have been sedated, as soon as you are awake, and you will receive a copy of the endoscopy report to take home. However, if a sample (biopsy) has been taken for examination the results may take a few weeks. It is a good idea to have someone with you when you speak to the endoscopist after the test since, if sedation has been used, people often find they forget everything that has been said to them and many do not recollect having the test at all. Further details of the results and any necessary treatment can be discussed with your general practitioner or hospital specialist – whoever recommended you to have the test.

What to expect after Diagnostic Gastroscopy (OGD)

After diagnostic gastroscopy (OGD) there are minimal side effects, but it is sensible that you are aware of the following:

Food and drink

Alcohol in combination with any sedation you may have received is more likely to make you much more sleepy that usual. If local anaesthetic was used in your throat, you should not eat or drink until normal sensation returns, usually within an hour of the procedure. A mildly sore throat is no cause for concern and should resolve within 24 hours. Normal food can be taken after the examination, though you may prefer light meals on the day of the examination. 


Abdominal pain is uncommon after gastroscopy. Some patients have discomfort due to wind in the stomach during the procedure but this subsides rapidly. If you are troubled by more than this, please consult your own GP or contact the Endoscopy Department.


If you have been given sedation during the procedure it will make you less alert than usual and you should therefore not drive or make any decisions for the rest of the day. You may resume normal activities on the day after the examination.


You may resume normal medications immediately after the gastroscopy. Please ask if you are not sure that a medication is safe. 

Things to report to your doctor

  • Severe pain or vomiting
  • Temperature greater than 38 degrees
  • Redness, tenderness and swelling at the site of the intravenous injection that persists

If you have any worries please do not hesitate to either contact the Endoscopy Department, your own GP or go to your nearest Accident & Emergency Department (taking a copy of the endoscopy report with you).