He was appointed as a consultant paediatric surgeon at Kings College Hospital in 1994. His main clinical interests are not only hepatobiliary diseases such as biliary atresia and choledochal malformation but also antenatally-diagnosed surgical malformation, such as abdominal wall defects and diaphragmatic hernia. 

He has been an editor for the Journal of Pediatric Surgery since 2008. He actively promotes medical writing and has published two editions of two general paediatric surgery textbooks (for the Oxford University Press and Springer); an international multi-author specialist book on paediatric liver and pancreatic disease; the 8th edition of the popular Rob & Smith’s Operative Pediatric Surgery and most recently a book on “Landmark Papers in Paediatric Surgery for CRC press. He has published over 300 predominantly research-orientated papers (H-index = 53) together with over 50 chapters on a variety of surgical topics. He has delivered guest invited lectures on all 6 continents.

He was elected President of the British Association of Paediatric Surgeons (BAPS) for 2016-18.