Fasting Guidelines

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What is fasting (NPO)?

Sometimes, your child must go without food or drink before certain procedures, scans, or tests.

Not eating or drinking before a test is called fasting. You might also hear it called NPO, which is short for a Latin phrase that means “nothing by mouth."

Always follow the fasting guidelines or NPO instructions given by your care team.

Why fasting is needed

There are several reasons your child may need to fast before a procedure or test:

Under general anesthesia, the normal cough or gag reflexes don’t work as well and food or liquid in the stomach can get into the lungs. This could cause pneumonia or other serious health problems.
Food or gas in the stomach or intestines can cause pictures to be blurry or hide issues in some types of scans.
Some scans or tests require avoiding certain foods, like fat or sugar, because it can interfere with test results.

It is hard to keep children from eating and drinking when they are hungry or thirsty. But fasting guidelines are in place to keep your child safe. It is important to follow them. Not following fasting guidelines can delay your child’s procedure. If you have questions about fasting or NPO instructions, talk to your care team.

General fasting guidelines

Below are some general guidelines for fasting. These apply to children who can eat or drink by mouth as well as those who have a feeding tube. Fasting guidelines can differ based on the type of test, so always follow your care team’s instructions.

NPO: Fasting guidelines for general anesthesia or IV sedation
1 hour before the procedure	STOP giving your child clear liquids* and CT contrast.
3 hours before the procedure	STOP giving your child breast milk.
6 hours before the procedure	STOP giving your child infant formula, Ensure® Clear, or milk (non-human).
8 hours before the procedure	STOP giving your child solid food, tube (enteral) feeds, Ensure®, or liquids not listed as approved clear liquids*.

*Approved clear liquids include:

Water
Clear fruit juice (apple juice or white grape juice)
Carbonated drinks with no particles, such as ginger ale or soda
Coffee and tea with no milk or creamer
Sports drinks (such as Gatorade^®)
Gelatin, such as Jell-O^®
Pedialyte^®
Frozen ice pops (not fruit bars)
Ensure^®Pre-Surgery

Please note that Ensure^® Clear nutrition drink and similar products are not approved clear liquids.

Your care team may give other instructions based on the type of test and your child’s medical needs.

Medicines by mouth before general anesthesia

On the morning of general anesthesia, give your child all medicines they would normally take unless your child’s care team tells you not to give them.

An exception to fasting guidelines: PET Scans

If your child is having a PET scan, your child should not have food or drink other than water or sugar-free flavored water for at least 4 hours before the scan. The sugar in other foods and drinks can interfere with the test. You may get additional NPO instructions if your child will have general anesthesia with the scan.

Usually, taking medicine with a sip of an approved clear liquid will not delay your child’s procedure. Medicines taken with any other liquid or solid food, such as yogurt or applesauce, will delay general anesthesia.

Your care team may give other instructions for fasting depending on the procedure or your child’s specific medical needs. Always follow the instructions given by your care team.

Questions to ask your care team

When should my child stop eating or drinking before the procedure?
If my child gets nutrition by feeding tube, are any changes needed to my child’s tube feedings?
Can my child chew gum or suck on hard candy?
When will my child be able to eat or drink after the procedure?
Are any changes needed to my child’s medicines?
What counts as a clear liquid?

Key points about fasting guidelines

Sometimes, your child must go without food or drink before anesthesia or sedation. This is called fasting or NPO; NPO is short for a Latin phrase that means “nothing by mouth".
Fasting guidelines are in place to keep your child safe. It is important to follow them.
Ask your child’s care team if you’re not sure what your child can eat or drink before a test or procedure.
NPO instructions can vary based on the type of procedure or a patient’s medical needs. Always follow the fasting guidelines given by your care team.

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The Together by St. Jude™ online resource does not endorse any branded product mentioned in this article.

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Reviewed: November 2024