Why Can't I Eat or Drink Before My Surgery?

The Ban on Food and Drink Is for Your Safety During Surgery

Patient with a respiratory mask on operating table
Westend61/Getty Images

If you are planning to have surgery you may have been told that you shouldn’t eat or drink for eight to 12 hours prior to your procedure. It is very important that you follow these instructions to avoid complications during and after your surgery.

Unless you have been told that it is ok to take your medications the morning before surgery with a few sips of water, no food or drink truly means no food or drink.

 None. Not a snack or even a sip of water.

2 Reasons Not to Eat or Drink Before Surgery

1) If your surgery will be in part of your gastrointestinal system, having food in your system could complicate the surgery and lead to infection.  Eating or drinking prior to your procedure could cause the surgery to be canceled.  In some cases, a bowel preparation is done, a process that completely empties your digestive tract to prepare for surgery.  To eat or drink after your bowel preparation could undo all of your efforts to empty your digestive tract.

2) If you have food or fluid in your stomach during your surgery, you could vomit while under anesthesia. The combination of anesthesia, which paralyzes the body, and intubation makes it possible for you to inhale the vomit into your lungs, which is called aspiration.  Asleep and paralyzed, your ability to cough, or even to spit vomit out of your mouth is taken away and the risk of aspiration is high.


Have you ever taken a bite of something and had it "go down the wrong pipe"? That is aspiration.  When it happens while you are awake, you cough, gag, maybe even vomit, but you get the food out of your airway.  This ability to react is gone when you are under anesthesia, so the best way to prevent this from happening is to not having anything in your stomach before surgery.

This can cause serious complications, such as pneumonia and difficulty breathing, which can compromise your recovery. 

Eating before surgery--when you have been told not to--can also lead to nausea and vomiting after surgery.  Vomiting after surgery can be extremely painful, as your incision site and your throat may already be sore from the surgery itself. 

Your Last Meal Before Surgery

You may be tempted to have a huge meal before you start your eight- to 12-hour fast. Do not give into the temptation, as it can completely defeat the purpose of fasting. Instead, have a light meal such as soup and salad for your final meal before surgery. A heavier meal takes longer to digest and negates the effect of abstaining from food and drink prior to surgery.

If your surgeon has said you should take your regular medications on the morning of your surgery, plan to do so with the smallest sip of water possible. Do not take your medication if the surgeon has not instructed you to do so, if you are unsure call the doctor's office or take them with you to the surgical center. Take care not to swallow water when you brush your teeth.

Leading Up to Surgery

If you are several days or weeks from surgery, try to make lean, protein-rich foods, such as pork, chicken, seafood or tofu/beans and low-fat dairy products a part of your diet.

Protein is an essential part of the healing that takes place after surgery.  

Hydrate, preferably with water, until your urine is clear and mostly colorless.  You may be pleasantly surprised by how you feel when you drink an adequate or ample amount of water--those little aches and pains that you believe to be normal may go away entirely--and you may feel more energetic.

A Few Words from Verywell

It seems simple, don't eat before surgery, but a truly amazing number of patients do not follow instructions when preparing for their surgery.  The risks of eating and drinking when you have been instructed not to do so are higher than you might imagine.

 It truly is important to avoid all food and drink at least eight hours prior to having anesthesia, as the alternative may be to develop severe pneumonia after surgery.

Continue Reading