Author or co-author of over 150 papers in peer-reviewed journals and 25 book chapters, Professor Barr is also active in national professional associations. A Fellow of the Royal Colleges of Surgeons of London and Edinburgh, he currently serves as a councillor and secretary of the British Medical Laser Association, and has been elected to the Council of the British Society of Gastroenterology (2005) and the Oesophageal Section (2005) and former member of the Endoscopy Committee of the British Society of Gastroenterology. His provides advice regarding endoscopic therapy in the oesophagus for the NICE.