Dr Sean Preston is Medical Director at The Princess Grace Hospital, part of HCA Healthcare UK. He graduated from St Mary's Hospital Medical School, Paddington in 1995. The majority of his postgraduate training was centred at Barts and the London NHS Trust (a major London Teaching Hospital), in addition to a year spent in Sydney as an Advanced Endoscopy Fellow, prior to his appointment as a Consultant at Barts in 2006.

His clinical practice includes the diagnosis and treatment of gastro oesophageal reflux disease (heartburn), Barrett's oesophagus, irritable bowel syndrome, inflammatory bowel disease, diarrhoea, constipation, bloating, in addition to diagnostic and therapeutic endoscopy of the oesophagus, stomach and colon. He has a keen interest in gut health and gastrointestinal microbiota (bacteria, viruses and fungi) and uses both diet, pre and probiotics in the achievement and maintenance of optimal conditions within the bowel. Clinical consultations are structured to allow patients sufficient time to explain all their symptoms and to fully understand for the cause of their concerns.

His PhD, undertaken at Cancer Research UK, London, outlined the role of stem cells in gastrointestinal cancers and led to several significant publications in the field.

He is Director of Endoscopy at Barts Health and his endoscopic expertise relates to gastroscopy, colonoscopy and endoscopic ultrasound and he is an accredited colonoscopist for the National Bowel Cancer Screening Programme (requiring a rigorous accreditation process and continual audit of key performance indicators). He has written numerous key papers and book chapters on gastrointestinal cancer and continues his research in Barrett's oesophagus.

Dr Preston also featured in the 2013 Tatler Doctors Guide of Britain's top 250 consultants and is in 2024's elite group of Spears 500 Top Recommended UK Private Doctors and Surgeons. He was President of the Gastroenterology and Hepatology Section of the Royal Society of Medicine from 2015-2017 and is currently Chairman of the Specialists' Committee for the Independent Doctors' Federation.

As a founding partner of London Digestive Health, within London Digestive Centre, he works within the framework of first class clinical team of other London Teaching Hospital Gastroenterologists, in addition to GI surgeons, Radiologists, Oncologists and a Dietician. 

Dr Preston is also the Chair of Digestive Diseases and Renal Department at HCA Healthcare UK.