Dr Gareth Parkes

Consultant Gastroenterologist


Personal profile


  • Queens’ College Cambridge BA, MA
  • Bart’s and the London Medical School - MBBS with distinction
  • King’s College London - PhD - The role of the gastrointestinal bacteria in the development of irritable bowel syndrome 
Health Matters Consultant Contributor


Inflammatory Bowel Disease 

I have had experience in three major centres in inflammatory bowel disease and now am part of a team of IBD specialists at the Royal London. I have published in this area and I am actively involved with clinical trials of novel biological therapies. I have experience in specialist IBD endoscopy, novel biologic agents and complex IBD patients. 

Irritable Bowel Syndrome 

I have an active interest in irritable bowel syndrome or IBS, in particular in the role that diet and the gut microbiota play in the causes and treatment for this condition. I have published widely in this field in particular in the role that probiotic preparations can have in the treatment of IBS. 


I have broad range of endoscopic experience and I am competent in a wide range of diagnostic and therapeutic procedures including in the diagnosis of cancer, ulcers, Barrett’s oesophagus, colitis, Crohn’s disease, diverticular disease and polyps. In particular I specialise in difficult colonoscopy and polypectomy as well as working as a trainer within the NHS. 


  • Parkes GC, Whelan K, Lindsay JO.Smoking in inflammatory bowel disease: impact on disease course and insights into the aetiology of its effect. J Crohns and Colitis 2014 Aug 1;8(8):717-25
  • Parkes GC, Rayment NB, Hudspith BN, Petrovska L, Lomer M, Brostoff J, Whelan K, Sanderson JD. Distinct microbial populations exist in the mucosa-associated microbiota of sub-groups of irritable bowel syndrome. Neurogastroenterol Motil. 2012 Jan;24(1):31-9
  • Parkes GC, Sanderson JD, Whelan K. Treating irritable bowel syndrome with probiotics: the evidence. Proc Nutr Soc. 2010 May;69(2):187-94. 2010 Mar 18.
  • Parkes GC, Sanderson JD, & Whelan, K. The mechanisms and efficacy of probiotics in the prevention of Clostridium difficile-associated diarrhoea. Lancet Infect Dis 2009;9:237-244
  • Parkes GC, Brostoff, J., Whelan, K. & Sanderson, JD. Gastrointestinal microbiota in irritable bowel syndrome: their role in its pathogenesis and treatment Am J Gastroenterol.2008; 103:1557-1567 
  • Lomer MC, Parkes GC, Sanderson JD. Review article: lactose intolerance in clinical practice--myths and realities. Aliment Pharmacol Ther 2008;27(2):93-103.

Professional Membership

  • British Society of Gastroenterology
  • European Crohn’s and Colitis Organisation
  • Royal College of Physicians

Clinical Interests

  • Inflammatory bowel disease 
  • Irritable bowel syndrome including the use of probiotics and dietary therapy 
  • Gastro-oesophageal reflux disease 
  • Indigestion 
  • Coeliac disease
  • Bowel cancer 
  • Colonic polyps 
  • Abnormal liver function

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