Fact sheetDiet specifications

Published on 1 Nov 2011

General diet - nil by mouth

This document is part of the ACI Diet Specifications for Adult Inpatients. It is not to be used for patient education.


To provide no oral intake from food or fluids.


No food or fluids are offered.


When ordered, as part of preparation for all patients undergoing general anaesthesia and various tests and procedures (e.g. endoscopy). May also be ordered when it is unsafe for a patient to eat (e.g. gastrointestinal perforation, dysphagia) or following gastrointestinal surgery.

Nutritional adequacy

Nutritionally inadequate.


No water jug to be left at bedside. No menu to be offered. No supplements to be ordered with this diet. No mid-meals to be served. Not to be combined with any other diet: this order overrules other diet orders. Contact dietitian if this diet used for more than two days.

A 2010 Cochrane review of pre-operative fasting found there was no evidence to suggest a shortened fluid fast results in an increased risk of aspiration, regurgitation or related morbidity compared with the standard fasting policy of nil by mouth from midnight.

A 2001 meta-analysis found there was no clear advantage in keeping patients nil by mouth after elective gastrointestinal resection and that early feeding may be of benefit.


Suitable for use in paediatrics.

Specific menu planning guidelines

Allowed Not allowed
Hot main dishesNone-
Sauces, graviesNone -
Starchy vegetables / pasta / riceNone -
Salads, dressingsNone-
Breads, cerealsNone -
Hot breakfast choicesNone -
Milk and cheeseNone -
MiscellaneousNone -


  1. Brady M, Kinn S, Stuart P, Ness V. Preoperative fasting for adults to prevent perioperative complications. Cochrane Database Sys Rev 2003;(4):CD004423.
  2. Ljungqvist O, Søreide E. Preoperative fasting. Br J Surg 2003;90(4):400-6.
  3. Lewis SJ, Egger M, Sylvester PA, Thomas S. Early enteral feeding versus “nil by mouth” after gastrointestinal surgery: systematic review and meta-analysis of controlled trials. BMJ 2001;323:773-6.
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