John is a Colorectal and General Surgeon and also a Senior Clinical Lecturer in Surgery at the University of Otago. He obtained his Fellowship in General Surgery after surgical training at Christchurch and other NZ Hospitals.

Following his fellowship, he completed subspecialty training in colon and rectal surgery at prestigious international institutions including St. Bartholomew's and the Royal London Hospital, Concord Repatriation General Hospital in Sydney, and The Royal Melbourne Hospital.

He holds fellowships with the Royal Australasian College of Surgeons, the Colorectal Surgical Society of Australia and New Zealand, and the American Society of Colorectal Surgeons. He has published and presented on various colorectal and surgical conditions nationally and internationally.

He specializes in laparoscopic “keyhole” surgery, which he has performed for over 20 years, offering improved patient recovery. Additionally, he is trained in the Da Vinci Robotic platform for robotic-assisted surgery.