NHS colonoscopy instructions: which foods are allowed?

NHS hospitals give different instructions about what patients can eat before a colonoscopy. These are the published rules I found, grouped by food.

This is part of my series comparing NHS colonoscopy preparation instructions.

Jump to: Salmon and other pink or oily fish · Red meat · Quorn · Cornflakes · Ready Brek · Crisps · Chips · Fruit · Vegetables · Beans, lentils and other pulses · Peeled potatoes

Salmon and other pink or oily fish

Red meat

Quorn

Only named Quorn instructions are counted, not generic references to tofu or mycoprotein.

Cornflakes

Ready Brek

Crisps

Wotsits, Quavers and similar snacks are not automatically treated as permission to eat ordinary potato crisps.

Chips

Fruit

Vegetables

Beans, lentils and other pulses

Peeled potatoes

Differences within individual NHS organisations

Some hospitals issue different instructions in different places. This doesn’t necessarily mean the same patient would receive both versions.

• Epsom and St Helier’s hospital dietary advice permits lean meat and some fruit and vegetables, while its Plenvu chart prohibits red meat and all fruit and vegetables.
• Calderdale and Huddersfield’s endoscopy page says to avoid red meat, while its Plenvu instructions permit lean beef, lamb, ham, veal and pork.
• Blackpool’s Moviprep instructions permit well-cooked beef/lamb/pork, while its Picolax instructions exclude red meat.
• Nottingham’s general low-fibre advice and vegan guidance set different rules for some foods.

Conflicting wording within one document

Some apparent differences are within a single document, rather than between hospitals. I have not included those documents in either column where the wording is contradictory.

• University Hospitals Birmingham’s low-residue sheet includes lamb in a permitted list but also says to avoid red meat.
• Barts Health’s diet sheet allows pork and veal but also includes a general red-meat exclusion.
• Tameside and Glossop’s leaflet allows cornflakes with milk on one page while its chart excludes cereals and milk products.
• Salisbury’s Picolax leaflet permits cornflakes in its detailed table despite a broader cereal warning.
• East Kent’s Moviprep/Plenvu leaflet permits pork/ham while also warning against red meat.

About this comparison

The research inventory contains 95 food-instruction records from 81 NHS organisations. This comparison focuses on standard colonoscopy guidance, excluding screening-specific and other specialist pathways. A hospital can appear on both sides where it has published different instructions.

The published instructions show variation but do not establish which rules improve bowel cleansing, nor what any individual patient is currently told to do. This is a comparison of patient information, not guidance to change the preparation prescribed for your own colonoscopy.

Research checked: 10 November 2026.