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Can I eat or drink before an operation?

Every operation is different. Whether you are allowed to eat or drink beforehand, and what you can have, will depend on the type of operation and anaesthetic you're having.

Before you have your operation, the healthcare professionals treating you will:

  • tell you if you can eat or drink before
  • tell you what foods and liquids you can have, if eating and drinking are allowed
  • tell you when to stop eating and drinking, if eating and drinking are allowed

Anaesthetic

Before having an operation, it's likely that you'll be given either a local or a general anaesthetic.

A local anaesthetic numbs the area being treated, so you do not feel any pain.

A general anaesthetic makes you unconscious so you cannot feel anything and you're not aware of what's going on during the operation.

Eating and drinking before a general anaesthetic

Usually, before having a general anaesthetic, you will not be allowed anything to eat or drink. This is because when the anaesthetic is used, your body's reflexes are temporarily stopped.

If your stomach has food and drink in it, there's a risk of vomiting or bringing up food into your throat. If this happens, the food could get into your lungs and affect your breathing, as well as causing damage to your lungs.

The amount of time you have to go without food or drink (fast) before you have your operation will depend on the type of operation you're having. However, it is usually at least 6 hours for food, and 2 hours for fluids. You'll be told how long you must not eat or drink for before your operation.

Chewing gum, including nicotine gum, should be avoided during this fasting period.

You may be told to avoid certain types of fluids, such as milk, or tea and coffee with milk added to them, before an operation. If you vomit after having these drinks, the liquid could get into your lungs and damage them. Clear fluids, such as water, are usually recommended.

Children

Children can drink some types of fluids (including water, pulp-free juice and tea or coffee without milk) up to 1 hour before surgery. Milk, fizzy drinks and smoothies are not allowed.

You can breastfeed your baby up to 4 hours before surgery. This includes expressed breast milk if your partner is looking after the baby.

Cows’ milk, formula milk and soya, oat and coconut milks are not allowed for 6 hours before surgery because they’re classed as foods.

Medical conditions

If you have a medical condition, such as diabetes, which means you need to eat and drink regularly, you should tell a healthcare professional before your operation.

You should also let them know if you're taking any medicines.

Local anaesthetic

If you're having a local anaesthetic, you should be allowed to eat and drink as normal before your procedure. But this may not be the case if you're having a procedure that involves your digestive system or bladder.

Further information:

Page last reviewed: 14 November 2023
Next review due: 14 November 2026