Ms Yvonne McKenzie

Qualifications

Post Graduate Diploma in Dietetics, MSc in Nutrition

GMC number: HCPCRegistered:DT07090

Practising since: 1998

Specialties

Dietetics, Nutrition, Gastrointestinal surgery, Nutrition

Consultation times

  • Thursday PM (The Manor Hospital, Oxford)
  • Variable (Nuffield Health Warwickshire Hospital)
  • Virtual appointments available.
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About

Yvonne McKenzie is a highly experienced clinical dietitian specialising in gastrointestinal (GI) disorders, Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), and coeliac disease, with over 25 years of practice in the dietary management of functional and organic bowel conditions. She has been delivering specialist dietetic services to adult patients in Oxford since 1998.

Yvonne has been affiliated with The Manor Hospital, Oxford, since 2007, where she provides evidence-based nutritional interventions including the Low-FODMAP diet, probiotic therapy, and specialized regimens for Small Intestinal Bacterial Overgrowth (SIBO) aimed at optimising gastrointestinal function and symptom management. Prior to this, she held a clinical role within the Oxford University Hospitals NHS Foundation Trust (1998–2008).

Her clinical work involves multidisciplinary collaboration with consultant gastroenterologists, colorectal surgeons, and general practitioners, supporting the management of conditions such as Bile Acid Diarrhoea (BAD), Pancreatic Exocrine Insufficiency (PEI), gastroparesis, food intolerances, malabsorption syndromes, and other functional gastrointestinal disorders. Since 2022, she has also been consulting at Nuffield Health Warwickshire Hospital.

Yvonne completed her postgraduate training in Nutrition and Dietetics at King's College London and Hammersmith Hospital (Imperial College Healthcare NHS Trust), institutions recognised for their advanced clinical and research training in nutritional sciences.

She is currently undertaking doctoral research, pursuing a PhD in Nutrition at The University of Manchester, with a focus on advancing clinical understanding of diet therapy for managing Bile Acid Diarrhoea (BAD) and evidence-based practice within the field of gastrointestinal nutrition.

For direct clinical enquiries:

Special interests

Yvonne provides personalised, evidence-based dietary treatment and management of gastrointestinal disorders or diseases in adults, optimising bowel health including stoma care, and nutritional adequacy:

Yvonne McKenzie specialises in:

  • Coeliac disease
  • Constipation
  • Diarrhoea
  • Diverticulosis
  • Excessive wind (flatulence) and bloating
  • Fatty liver disease
  • Food intolerances associated with gut symptoms or gut symptoms that have not yet been medically explained
  • Gallbladder: dietary considerations before or after its removal
  • Gastroparesi
  • Irritable Bowel Syndrome (IBS)/disorder of gut-brain interaction
  • Pancreatic exocrine insufficiency
  • Reflux.

Other medical issues Yvonne often advises on:

  • Assessment of unintentional body weight change
  • Bile acid diarrhoea
  • Correcting and preventing nutritional deficiencies such as vitamin D and iron 
  • Health eating and lifestyle 
  • Osteopenia/osteoporosis 
  • Preservation of skeletal muscle mass through diet and lifestyle.

Other interests

  • Diet therapy for managing bile acid diarrhoea
  • Dietary fibres
  • FODMAP diet
  • IBS Probiotics.

Languages spoken

English

Treatments and tests offered by Ms Yvonne McKenzie at Nuffield Health

  • Dietician

Locations Ms Yvonne McKenzie works with

  •  

    Beech Road, Headington, Oxford, OX3 7RP

    01865 307777
    Overall rating
    Good
     
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  •  

    The Chase, Old Milverton Lane, Leamington Spa, CV32 6RW

    01926 427971
    Overall rating
    Good
     
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Related experience

Research

Yvonne’s PhD research explored diet therapy for managing bile acid diarrhoea, Sept 2019 to 2025, supervisors: Dr Sorrel Burden and Prof Chris Todd. One-third of people treated for diarrhoea-predominant irritable bowel syndrome actually have bile acid diarrhoea (BAD). BAD is an under-recognised, under-appreciated, and under-researched medical condition estimated to affect about 1% of the UK’s general adult population.

Yvonne McKenzie was a co-investigator for an NIHR funded research study: Management of diarrhoea in patients with stable ulcerative colitis with low FODMAP diet, amitriptyline, ondansetron or loperamide: the MODULATE RCT, led by Professor Alex Ford. Published March 2025: https://doi.org/10.3310/GHFE4871

As a diet expert, Yvonne McKenzie has made many national contributions to improve healthcare in IBS and BAD over the last 10+ years:

James Lind Alliance priority setting partnership, funded by the British Society of Gastroenterology and Guts UK: Top 10 research priorities for IBS. Published June 2023: https://gutscharity.org.uk/wp-content/uploads/2023/06/IBS-The-UKs-Top-10-Research-Priorities-FINAL.p...

With the National Institute for Health and Care Excellence: -SeHCAT (taurocholic [75 selenium] acid) for diagnosing bile acid diarrhoea. Diagnostics guidance DG44. Published Nov 2021. https://www.nice.org.uk/guidance/dg44 -Irritable bowel syndrome in adults: diagnosis and management. Clinical guideline CG61 Update 2016. http://www.nice.org.uk/Guidance/CG61 -Irritable bowel syndrome in adults. Quality Standard QS114. Published Feb 2016. https://www.nice.org.uk/guidance/qs114

With the BDA:

First author of the British Dietetic Association's evidence‐based practice guidelines for the dietary management of IBS in adults (2016 update, 2012).

Publications in peer-reviewed scientific journals:

Staudacher HM, Costas-Batlle C, Phillips M, Anderson S, McKenzie, YA, Lomer MCE. Dietary modifications in patients with non-inflammatory bowel disease diarrhoea: a summary of the evidence and practical considerations. Frontline Gastroenterology. 2025 June.

McKenzie YA, Kelman L, O’Connor M, Todd C, Walters JRF, Burden S. Diet therapy (The 8x5 Diet) for adults living with bile acid diarrhoea: protocol for a feasibility randomised controlled trial. BMJ Open. 2025; 0:e097973. 2025 March. doi: 10.1136/bmjopen-2024-097973.

French C, McKenzie Y, Stanmore E, Burden S. Are Mobile Apps Effective at Targeting Physical Activity or Malnutrition in Community-Dwelling Older Adults? A Systematic Review and Meta-Analysis. Journal of Aging and Physical Activity. 2024 Dec;1(aop):1-3. doi: 10.1123/japa.2023-0449.

McKenzie YA, French C, Todd C, Burden S. Food intolerance related to gastrointestinal symptoms amongst adults living with bile acid diarrhoea: A cross‐sectional study. Journal of Human Nutrition and Dietetics. 2024 Feb;37(1):79-93. doi: 10.1111/jhn.13232.

Black CJ, McKenzie YA, Scofield-Marlowe M, Setter P, Tarpey M, Ford AC, West H, Southey E, Thompson J, Corsetti M, Everitt HA. Top 10 research priorities for irritable bowel syndrome: results of a James Lind Alliance priority setting partnership. The Lancet Gastroenterology & Hepatology. 2023 June;8(6):499-501. doi: 10.1016/S2468-1253(23)00072-9.

McKenzie YA, Sremanakova J, Todd C and Burden S. Effectiveness of diet, psychological, and exercise therapies for the management of bile acid diarrhoea in adults: A systematic review. Journal of Human Nutrition and Dietetics. 2022 March;35:1087–1104. doi: 10.1111/jhn.13005.

Rej A, Avery A, Ford AC, Holdoway A, Kurien M, McKenzie Y, Thompson J, Trott N, Whelan K, Williams M, Sanders DS. Clinical application of dietary therapies in irritable bowel syndrome. Journal of Gastrointestinal & Liver Diseases. 2018 Sep 1;27(3). doi: 10.15403/jgld.2014.1121.273.avy.

McKenzie YA, Bowyer RK, Leach H, Gulia P, Horobin J, O'Sullivan NA, Pettitt C, Reeves LB, Seamark L, Williams M, Thompson J. British Dietetic Association systematic review and evidence‐based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update). Journal of Human Nutrition and Dietetics. 2016 Oct;29(5):549-75. doi: 10.1111/jhn.12385.

McKenzie YA, Thompson J, Gulia P, Lomer MC, (IBS Dietetic Guideline Review Group on behalf of Gastroenterology Specialist Group of the British Dietetic Association). British Dietetic Association systematic review of systematic reviews and evidence‐based practice guidelines for the use of probiotics in the management of irritable bowel syndrome in adults (2016 update). Journal of Human Nutrition and Dietetics. 2016 Oct;29(5):576-92. doi: 10.1111/jhn.12386.

McKenzie YA, Alder A, Anderson W, Wills A, Goddard L, Gulia P, Jankovich E, Mutch P, Reeves LB, Singer A, Lomer MC. British Dietetic Association evidence‐based guidelines for the dietary management of irritable bowel syndrome in adults. Journal of Human Nutrition and Dietetics. 2012 Jun;25(3):260-74. doi: 10.1111/j.1365-277X.2012.01242.x.

Books

Yvonne has written many chapters on IBS:

  • BDA Manual of Dietetic Practice: 5th (2014), 6th (2019) and 7th (due May 2026) editions
  • BDA Dietetic and Nutrition Case Studies (2016)
  • Oxford Handbook of Nutrition & Dietetics, 3rd edition (2021).

Memberships

  • British Dietetic Association (BDA)
  • British Society of Gastroenterology
  • Primary Care Society for Gastroenterology
  • Health and Care Professions Council

Insurers Ms Yvonne McKenzie works with

Ms Yvonne McKenzie works with the following private medical insurance providers:

  • Aetna
  • Aviva Health
  • AXA Health
  • AXA - Global Healthcare
  • Benenden Health
  • Bupa
  • Bupa Global
  • Cigna
  • Cigna International
  • CS Healthcare
  • Healix
  • Health-on-Line
  • PHC
  • Simplyhealth
  • Standard Life
  • Vitality Health (Pru Health)
  • WPA
  • The Exeter

Declaration

Ms Yvonne McKenzie does not hold a share or financial interest in this hospital, another Nuffield Health hospital or the company.

Ms Yvonne McKenzie does not have a share or financial interest in equipment used at this hospital or another Nuffield Health hospital.

Ms Yvonne McKenzie does not hold any paid advisory role(s) at this hospital or on behalf of Nuffield Health.