Dr Gary Mackenzie

Dr Gary Mackenzie

Consultant Gastroenterologist


Specialises in

  • Gastrointestinal cancer and early detection of bowel cancer
  • Inflammatory bowel disease
  • Capsule endoscopy (pillcam)
  • Iron deficiency anaemia
  • Reflux disease

Also available for:

Virtual consultations:

I am a Consultant Gastroenterologist and a colorectal cancer screening colonoscopist. Within Gastroenterology, I have an interest in acid reflux and minimally invasive diagnostics and therapy and I am an endoscopy trainer. I have been a bowel cancer screening colonoscopist since early 2014 and I am now a mentor within the National Bowel Cancer Screening Programme.

Until recently, I was Lead Clinician for Endoscopy and Gastroenterology and in the past I have been Lead Clinician for Digestive Diseases and General Surgery as well as Endoscopy Training Lead. I am now focusing on cancer screening and minimally invasive diagnostic techniques.

I set up and I run the local capsule endoscopy service for investigation of the small bowel examining for causes of abdominal pain and anaemia. I also set up and run local pH and manometry services for the treatment of acid reflux and swallowing disorders.

I trained at St Bartholomew's Hospital in London after previously obtaining a first class honours degree in epidemiology and statistics from the University of London before choosing a career in Gastroenterology. Subsequently I was awarded a PhD from University College London for studies into diagnosis of gastro-oesophageal reflux disease, Barrett's oesophagus and the development of gastrointestinal cancer and their treatment.


General Medical Council Number: C4412438

Treatment information

Some of the principal treatments carried out by Dr Gary Mackenzie at Spire include:


Other treatments

  • I treat children and young people from 16 to 18 years old  

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Important information about COVID-19 tests

COVID-19 testing or antibody tests are not available as a standalone service at Spire Gatwick Park Hospital.


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Additional information

Gastrointestinal cancer
Inflammatory bowel disease

Special clinical interests: Abdominal pain, dyspepsia, early detection of bowel cancer, GI bleeding, iron deficiency anaemia, reflux disease.

Professional memberships

British Medical Association

Colonoscopist and Mentor, National Bowel Cancer Screening Programme

Fellow of the Royal College of Physicians

Medical Protection Society

Professional leadership

Mentor within the National Bowel Cancer Screening Programme
Lead Clinician for Digestive Diseases and General Surgery
Lead for local Capsule Endoscopy and pH & Manometry Services

I am a member of the local Research and Development Committee and continue to write and publish articles as described above.


"Radiofrequency ablation is an effective treatment for HGD in Barrett's oesophagus after failed PDT". Dunn JM, Banks MR, Oukrif D, Mackenzie GD, Thorpe S, Rodriguez-Justo M, Winstanley A, Bown SG, Novelli MR, Lovat LB.Lasers Med Sci. 2013 May;28(3):707-15.

Ben Warner, Gary Mackenzie. A rare case of a dual diagnosis of liver disease. J Med Cases, 2013; 4 (6): 362-364.

S Sithamparanathan, Z Hasan A Bakshi, G Mackenzie. Anorexia Nervosa complicated by surgical emphysema and deranged LFTs GastroHep Online, Feb 2012.

Image cytometry accurately detects DNA ploidy abnormalities and predicts late relapse to high grade dysplasia and adenocarcinoma in Barrett's oesophagus following photodynamic therapy. Accepted British Journal Cancer, March 2010. (BJC MD/2010/3063R (102))

Optimal conditions for successful ablation of high-grade dysplasia in Barrett's oesophagus using aminolevulinic acid photodynamic therapy. Mackenzie GD, Dunn JM, Selvasekar CR, Mosse CA, Thorpe SM, Novelli MR, Bown SG, Lovat LB. Lasers Med Sci. 2009 Sep;24(5):729-34.

Elastic scattering spectroscopy for detection of cancer risk in Barrett's esophagus: experimental and clinical validation of error removal by orthogonal subtraction for increasing accuracy. Zhu Y, Fearn T, Mackenzie G, Clark B, Dunn JM, Bigio IJ, Bown SG, Lovat LB. J Biomed Opt. 2009 Jul-Aug;14(4):044022.

Media Coverage



Consultant Gastroenterologist and National Bowel Cancer Screening Colonoscopist at Surrey and Sussex Healthcare.

I am married to Katie and have three children Ben, Luke and Grace. I also enjoy rugby and coach my son’s rugby team.