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Fasting before your general surgery

You have been admitted under the General Surgery department. Your safety and well being is of utmost priority to us. Your doctors have reviewed you and require you to be fasted temporarily. It is very important for patients to have an empty stomach for certain conditions, or in certain scenarios such as:

Pending investigations

You may require an injection of contrast material for some scans. This allows us to better visualize certain organs to help find out what is troubling you. If we find anything serious, fasting will also allow your doctors to arrange for further surgery or procedure as soon as possible.

The nursing staff will inform you how many hours you need to fast prior to the scan. Sometimes the scans timings are not fixed as the radiology department is busy, but your doctors will do everything they can to expedite the scan and ensure you are fed as soon as the scan is complete, and no further intervention is required.

Need for urgent procedures e.g., endoscopy

Procedures such as endoscopy will require your stomach and/or colon to be empty for clearer visualization. You may be given strong laxatives to help clear the bowels before the procedure. This helps in reducing and/or avoiding the need for a repeat scope due to poor visibility.

Depending on what the scope finds, we will allow you to eat as soon as possible after the scope.

Before General Anesthesia

It is important to fast before any procedure/surgery that requires general anaesthesia due to the risk of aspiration.
Aspiration is when food, drinks, or stomach contents enters the lungs instead of your stomach and can cause lung infections.

Failure to comply with fasting may delay your procedure by 6 to 8 hours. Please ask the staff if you have any concerns about the duration of fasting.

Occasionally if you are listed for an emergency procedure the waiting time may be longer than 6 to 8 hours due to the queue for the emergency operating room (OR). If so the staff will continuously liaise with the OR to get a timing and fast you only as necessary.

Certain surgical conditions

You may have come into hospital for symptoms such as abdominal pain, abdominal bloating or vomiting. Management of certain conditions may require you to be fasted temporarily.

Review by Surgery Team

The surgery team will review you every morning and will advise if you could be started on any dietary intake as soon as it is deemed safe to do so. This may involve clear fluids/soup followed by coffee/tea/milo and eventually solid food. We thank you for your understanding and compliance to the team’s management.


I have not eaten since I was admitted and I feel very hungry, when can I eat again?
You may be fasted temporarily while waiting for investigations/procedures to be done. You can eat as soon as your doctors feel you are safe and ready to do so. In some conditions or after certain surgeries, feeding may not be resumed immediately, and you may only be allowed to have fluids initially. This is to ensure that your bowels can tolerate fluids before escalating to solid food. Taking large meals immediately may lead to unpleasant ymptoms such as abdominal bloating and vomiting if your intestines have not resumed most of its functions.

I am elderly and feel weak as I have not eaten, is fasting safe?
It is perfectly safe to be fasted when you are hospitalized, your doctors will keep you hydrated with
intravenous fluids and your blood glucose levels will be checked regularly. Feeding will be resumed as soon as possible once it is safe to do so. If prolonged continued fasting (more than a few days) is anticipated and your condition does not allow you to consume orally, your doctors may consider you for parenteral nutrition (nutrition given intravenously). In all of these situations the surgical team will provide clear instructions to you or your designated family member.

I have been fasted, but I was told there is no confirmed timing for my scan/surgery, when will it get done?
We try our best to expedite your investigations or procedures. Unfortunately, in view of the very high patient load in Singapore General Hospital, scans and emergency operation slots are triaged according to medical urgency. We seek for your understanding in the event that your scan or procedure/surgery are delayed. If your investigation or procedure is scheduled greater than 6 to 8 hours later, we will allow some diet before fasting you again.

Will fasting impede my recovery?
I am worried my body will not receive required nutrients.
Our bodies have reserves to sustain bodily functions for at least a few days. Fasting will not affect your speed of recovery. If fasting is anticipated to be prolonged, your doctors will consider giving you nutrition in other ways, such as intravenously.

Can I take my existing oral medications if I am kept fasted?
This is dependent on the reason why your doctor kept you fasted. Our team has a record of all your old medications and will restart them when safe to do so. If you are not able to tolerate oral medications and require these medications, your medical team will ensure you receive a comparable medication in an intravenous form.

Can I eat immediately after my scan or procedure is done?
Your doctor will review the scan or procedure findings once they are done. If there are no plans for further scans or procedures and it is safe to do so, you will be allowed to eat after. Please give the team some time to review the results and we will update you as soon as we can. Please do not eat immediately because should you require further interventions, we can expedite it if you remain fasted.

How often will the medical team update me or my family on my feeding plans?
The medical team usually does morning rounds everyday between 730 10am. We will update you of results and subsequent management plan then. This also includes feeding plans. If you have further questions,  please contact the ward staff.