John is a Consultant Surgeon at the Academic Department of Abdominal Wall and Upper GI Surgery, North Devon District Hospital, Barnstaple, Honorary Associate Professor and Senior Clinical Tutor at the University of Exeter Medical School, and an NIHR Exeter BRC Senior Investigator Fellow.

He qualified from the University of Nottingham in 2007 and trained in surgery in Oxford. He undertook his PhD in genomics and clinical informatics at the Wellcome Trust Centre for Human Genetics and the Department of Oncology, was an Honorary Clinical Lecturer in Surgery, NIHR Oxford BRC Senior Clinical Research Fellow in Oesophagogastric Informatics, and Lecturer in Clinical Medicine at Corpus Christi College, at the University of Oxford.

He was appointed as a Consultant in North Devon in 2019. His clinical interests are complex and robotic abdominal wall and hiatal hernia surgery, and chronic pain after hernia surgery. His research is focussed on augmenting decision-making in hernia surgery for patients and surgeons, and assessing and improving functional outcomes. He is Chief Investigator of the BHS Registry research programme.