What is Gastroscopy?
Gastroscopy, or Oesophago-gastro-duodenoscopy (OGD), or Upper GI endoscopy is a procedure that uses a long flexible tubular instrument with a light source, inserted via the mouth, to assess the lining of the food pipe, stomach and early small intestine or the duodenum so we can examine for any abnormalities.
It is done as a Day Surgery procedure, which takes about 10-15 minutes approximately. It is done under moderate sedation, which means that the patient will be given medications into the vein to make them feel relaxed, painless and drowsy. It is also possible to do the procedure under local anaesthesia.
During the scope, air is blown into the stomach and helps us to see more clearly, which may cause mild abdominal discomfort and burping but will resolve. We will examine and do additional procedures (which may include biopsy or do tests for detecting the presence of ulcer-causing bacteria: Helicobacter pylori), as required depending on what we find.

What are the most common reasons for this procedure?
- Screening for oesophagus or stomach cancer
- Family history of bowel cancer
- Family history of stomach cancer
- Family history of high-risk cancers
- Surveillance after cancer surgery
- Loss of weight
- Loss of appetite
- Early satiety or feeling of fullness after little food intake
- Black stools or melena (which suggests the presence of ulcer)
- Abdominal pain or discomfort
What should the patient do before the procedure?
The patient should fast overnight, prior to the procedure.
Meanwhile, please inform us about any specific medical conditions the patient has (e.g. diabetes, hypertension, heart valves, blood thinner medications, etc.), since that will require more special instructions.
What should the patient do after the procedure?
Immediately after the scope, we will observe the patient in the recovery room and monitor them closely. If certain procedures were done during the scope, then certain medications has to be held off temporarily – which we will clearly instruct before discharging the patient.
If biopsy or tests were done, then the histology/results of the same will have to be traced at the next clinic visit.
We will recommend that the patients arrange for a family member or a driver to bring them back home after the scope, since it is unsafe to drive or operate any machinery for about 8-12 hours after the procedure due to the sedation medication given during the procedure. However, if the procedure is done under local anesthesia, the patient can go home alone on their own. Patients can also resume a normal diet after recovery.
Are there complications that might arise from this procedure?
Some patients might experience abdominal cramps or bleeding, especially when biopsy is done. A very small number of patients might also experience perforation of the bowel.
However, the incidence of the above complications is very low – about one in 10,000, and if it happens, then the patient may require emergency surgery. While it may be catastrophic, the procedure is overall considered to be safe in experienced hands.
What should the patient expect a few days after the procedure?
During the patient’s next clinic visit, we will provide them with scope pictures taken during the procedure, as well as some histology report, and proceed with further management. Depending on the findings, we might also recommend follow-up scopes in specified intervals.
Sometimes, if an ulcer-causing bacteria is found, then we will treat it (using anti-H. pylori triple therapy regimen) to eradicate the infection. After 8 weeks, we will perform further test (urea breath test) to confirm that it has indeed been eradicated.
Written by Dr Natarajan Suresh Khanna