Published NHS patient instructions grouped by when they say to start a low-fibre or low-residue diet before colonoscopy. This comparison focuses on standard, non-extended preparation pathways. Instructions specifically intended for extended preparation, previously failed bowel cleansing or other specialist needs have been excluded. Where an organisation publishes different routine instructions, it may appear in more than one group.
Sources identified up to 6 November 2026; some older documents are labelled. These documents may differ from the instructions currently issued to individual patients. “0 days” means that no separate low-fibre diet was specified in the published instructions examined. It does not mean no fasting or other dietary restriction.
Guidelines and research evidence
- European Society of Gastrointestinal Endoscopy (ESGE) guideline (2019) – recommends a low-fibre diet on the day preceding colonoscopy. Endorsed by the British Society of Gastroenterology.
- Systematic review and meta-analysis (2025) – five randomised trials involving 2,248 patients found no statistically significant difference in bowel-cleansing quality between one-day and two- or three-day low-residue diets; shorter diets were better tolerated.
- US Multi-Society Task Force consensus recommendations (2025) – recommend restricting dietary changes to the day before colonoscopy for ambulatory patients at low risk of inadequate bowel preparation.
0 days: no separate low-fibre diet specified in the published instructions
- NHS Tayside (diagnostic colonoscopy booklet; no low-fibre phase stated)
- Royal Surrey NHS Foundation Trust (Plenvu, March 2026; no low-fibre phase stated) [other published leaflets checked also omit a low-fibre phase]
2 days before colonoscopy
- Ashford and St Peter’s Hospitals (Moviprep morning)
- Barts Health (diet and bowel preparation guide)
- Bedfordshire Hospitals (Luton and Dunstable) (Moviprep; older officially hosted patient leaflet) [older/historical source]
- Blackpool Teaching Hospitals (Picolax (PL543), also covers sigmoidoscopy)
- Cardiff and Vale University Health Board (Moviprep) [older/historical source]
- Frimley Health (Citramag preparation guidance, approved May 2026)
- Gateshead Health NHS Foundation Trust (South of Tyne historical bowel cancer screening leaflet) [older/historical source]
- Gloucestershire Hospitals (Moviprep – afternoon gastroscopy and colonoscopy)
- Imperial College Healthcare (Low residue diet + How to take Moviprep)
- Isle of Wight NHS Trust: Plenvu afternoon; Plenvu morning
- James Paget University Hospitals (Klean-Prep)
- Kettering General Hospital NHS Foundation Trust (colonoscopy instructions) [verified in April 2025 web archive; current page may be inaccessible]
- Leeds Teaching Hospitals (MOVIPREP morning appointment – gastroscopy and colonoscopy)
- Liverpool University Hospitals (Moviprep afternoon)
- Mersey and West Lancashire (St Helens/Whiston) (Combined gastroscopy and colonoscopy; older patient booklet) [older/historical source]
- NHS Dumfries and Galloway: Colonoscopy with Moviprep; Colonoscopy with Picolax; Colonoscopy with Plenvu
- NHS Lothian (Moviprep patient instructions, historical NHS-authored leaflet) [older/historical source]
- North Tees and Hartlepool (Senokot and Picolax)
- Oxford University Hospitals (Colonoscopy booklet)
- Royal Cornwall Hospitals NHS Trust (Klean Prep bowel preparation) [older/historical source]
- Salisbury (Picolax two-sachet preparation)
- Sheffield Teaching Hospitals NHS Foundation Trust (colonoscopy preparation leaflet)
- South Tyneside and Sunderland NHS Foundation Trust (South of Tyne historical bowel cancer screening leaflet) [older/historical source; shared-service leaflet]
- Surrey and Sussex Healthcare NHS Trust: Citramag and Senna [older/historical source]; Moviprep morning [older/historical source]
- The Royal Marsden (Citramag and senna)
- The Shrewsbury and Telford Hospital (Plenvu morning)
- United Lincolnshire Teaching Hospitals (How to take your bowel preparation prior to endoscopic procedure)
- University Hospital Southampton (Moviprep afternoon)
- University Hospitals Coventry and Warwickshire (Colonoscopy patient booklet)
- University Hospitals Dorset (Plenvu morning)
- University Hospitals of Derby and Burton (Picolax: Royal Derby and Queen’s Hospital Burton)
- Whittington Health (Picolax instructions)
- Worcestershire Acute Hospitals (Colonoscopy prep – Senna and two CitraFleet sachets)
3 days before colonoscopy
- Airedale NHS Foundation Trust (Endoscopy FAQ, low-residue diet) [where possible]
- Aneurin Bevan University Health Board (How to take bowel prep – Plenvu, afternoon appointment)
- Barking, Havering and Redbridge University Hospitals (Moviprep morning)
- Blackpool Teaching Hospitals (Picolax (PL1614) – one published pathway)
- Bradford Teaching Hospitals (Your Colonoscopy, Sep 2026 quick guide)
- Bristol Royal Infirmary (University Hospitals Bristol and Weston) (Colonoscopy examination (Bristol Royal Infirmary, Queen’s Day Unit))
- Chesterfield Royal Hospital (Moviprep)
- Dartford and Gravesham NHS Trust: Darent Valley Hospital colonoscopy leaflet; Queen Mary’s Hospital Sidcup colonoscopy leaflet
- East Cheshire NHS Trust (Taking Moviprep oral bowel cleansing agents safely and effectively for colonoscopy/flexible sigmoidoscopy)
- East Kent Hospitals (Moviprep / Plenvu)
- Epsom and St Helier University Hospitals NHS Trust (colonoscopy/flexible sigmoidoscopy dietary advice) [official Word document; browser access may be restricted]
- Guy’s and St Thomas’ (Colonoscopy diet advice and bowel preparation)
- Hampshire Hospitals NHS Foundation Trust: Moviprep bowel preparation, morning appointment; Picolax bowel preparation, morning appointment; Plenvu bowel preparation, AM and PM appointments
- Homerton Healthcare NHS Foundation Trust (Colonoscopy diet advice and bowel preparation)
- London North West University Healthcare NHS Trust (historical St Mark’s food list) [older/historical source]
- NHS Forth Valley (Plenvu Bowel Preparation)
- NHS Golden Jubilee (Preparing for colonoscopy and flexible sigmoidoscopy v17)
- NHS Western Isles (Plenvu preparation instructions)
- Northern Care Alliance NHS Foundation Trust (Salford Royal Picolax colonoscopy leaflet)
- Nottingham University Hospitals (Bowel Preparation)
- Portsmouth Hospitals University NHS Trust (Endoscopy Department: Bowel Preparation – Picolax) [older/historical source; start day inferred from preparation timetable]
- Royal Cornwall Hospitals NHS Trust: Moviprep bowel preparation, bowel cancer screening; Plenvu bowel preparation, bowel cancer screening; Plenvu bowel preparation, general endoscopy (current leaflet)
- Royal Devon University Healthcare (Moviprep – afternoon colonoscopy/flexible sigmoidoscopy)
- Royal Free London (Having a colonoscopy)
- Royal United Hospitals Bath (Plenvu: bowel preparation – morning appointment)
- Salisbury: Klean-Prep instructions; Picolax three-sachet preparation
- Sherwood Forest Hospitals (Standard Plenvu preparation)
- St George’s University Hospitals (Colonoscopy with Plenvu)
- The Christie (Instructions for taking PLENVU bowel preparation)
- The Dudley Group NHS Foundation Trust (MoviPrep standard colonoscopy)
- University College London Hospitals (Morning colonoscopy with Plenvu)
- University Hospitals Birmingham (How to prepare your bowel for colonoscopy taking Plenvu)
- University Hospitals of Leicester (Low-residue/fibre diet)
- University Hospitals of North Midlands (Bowel preparation PDF)
- West Suffolk (Colonoscopy – outpatients)
- Whittington Health (Plenvu for Morning Appointments)
- Worcestershire Acute Hospitals (How to take Plenvu bowel prep)
- Wrightington, Wigan and Leigh Teaching Hospitals (Having a colonoscopy)
4 days before colonoscopy
- Buckinghamshire Healthcare NHS Trust (Low fibre diet for a flexible sigmoidoscopy or colonoscopy, with Moviprep instructions) [start day inferred from preparation timetable]
- Cambridge University Hospitals (Plenvu morning (derived from medication schedule)) [start day inferred from preparation timetable]
- Chelsea and Westminster Hospital (Colonoscopy)
- King’s College Hospital NHS Foundation Trust (bowel cancer screening; morning appointment) [start day inferred from preparation timetable]
- Kingston and Richmond (Bowel preparation before colonoscopy (Plenvu))
- North Cheshire and Mersey NHS Foundation Trust (shared screening-service booklet) [start day inferred from preparation timetable]
- Northumbria Healthcare (Colonoscopy preparation)
- Surrey and Sussex Healthcare NHS Trust (Plenvu) [start day inferred from preparation timetable]
- Torbay and South Devon NHS Foundation Trust (shared Devon patient leaflet) [shared-service leaflet]
- University Hospitals Plymouth NHS Trust (shared Devon patient leaflet) [shared-service leaflet]
- Wirral University Teaching Hospital NHS Foundation Trust (shared screening-service booklet) [start day inferred from preparation timetable]
5 days before colonoscopy
- Dorset County Hospital (Picolax standard morning)
- East and North Hertfordshire Teaching (Colonoscopy/Flexible Sigmoidoscopy – Plenvu)
- Norfolk and Norwich University Hospitals (Klean-Prep morning)
- North Cumbria Integrated Care (Endoscopy: Moviprep – morning) [preferred duration, not mandatory]
- Sandwell and West Birmingham Hospitals (PLENVU laxative instructions – afternoon appointment)
- University Hospitals of Morecambe Bay (Senna and Picolax)
- University Hospitals Sussex (Low residue diet)
- Worcestershire Acute Hospitals (How to take Moviprep bowel prep)
- York and Scarborough Teaching Hospitals (Having a colonoscopy, Plenvu)
7 days before colonoscopy
- Bolton NHS Foundation Trust (General colonoscopy leaflet (October 2026)) [preferred duration, not mandatory]
Other timings, ranges or conflicting instructions
These entries cannot reliably be assigned a single start day measured from the colonoscopy date.
- Calderdale and Huddersfield (at least 3 days: Bowel preparation instructions using Plenvu – afternoon procedure) [at least three days]
- East Sussex Healthcare (3–5 days: Plenvu morning)
- Milton Keynes University Hospital NHS Foundation Trust (low-fibre diet starts two days before taking bowel preparation) [days are counted before bowel preparation, not before colonoscopy]
- Royal Berkshire (3–4 days: Colonoscopy explained)
- Somerset NHS Foundation Trust (3–4 days: historical Yeovil diet sheet) [older/historical source]
- South Warwickshire University NHS Foundation Trust: endoscopy page: two days [conflicts with separate three-day diet sheet]; linked diet sheet: three days [conflicts with endoscopy page]
- Tameside and Glossop Integrated Care (at least 3 days: low-residue diet) [at least three days]
Some links are to older NHS-authored leaflets held in public archives or document mirrors. Please follow the instructions you receive from your clinical team, not this comparison list.