Dr Clarence Kerrison
Dr Kerrison completed his medical training at the University of Otago, followed by specialist training in Gastroenterology and Hepatology at hospitals across New Zealand. He then undertook a fellowship in advanced interventional endoscopy at Westmead Hospital, Sydney - Australasia's leading tertiary endoscopy unit - under Professor Michael Bourke, a world-recognised leader in the field. He maintains an active clinical research affiliation with Westmead Clinical School, University of Sydney, contributing to an internationally recognised programme of research and publication in advanced endoscopy. Dr Kerrison is passionate about gastrointestinal cancer screening and early detection, believing that finding disease earlier and making screening accessible. He is a member of Hei Ahuru Mōwai, the national Māori cancer leadership body and national leadership groups reflecting his commitment to equitable cancer outcomes. Born and raised in the Bay of Plenty, Dr Kerrison now calls Tauranga home, where he and his wife are raising their children and are active members of the local community.
Areas of Specialisation:
- Endoscopy (Gastroscopy & Colonoscopy)
- Endoscopic Mucosal Resection (EMR) & Endoscopic Submucosal Dissection (ESD) for treatment of early cancers of the colon, stomach or oesophagus
- Per Oral Endoscopic Myotomy (POEM) for Achalasia
- Gastric Per Oral Endoscopic Myotomy (G- POEM) for gastroparesis
- Zenker's Per Oral Endoscopic Myotomy (Z- POEM) for Zenker's diverticulum
- Endoscopic Ultrasound (EUS) - for stomach, pancreas, biliary or liver lesion assessment; coeliac plexus blocks.
- Endoscopic Retrograde Cholangiopancreatography (ERCP) for bile duct stones, strictures, or pancreatic stones or strictures
- Bowel cancer screening
- Barrett's Oesophogus Screening and Surveillance
- Endoscopic screening for genetic and familial gastrointestinal cancers
- Inflammatory bowel disease
- Chromoendoscopy
- Wireless capsule endoscopy - for small bowel bleeding or inflammation
- Gastro-oesophageal reflux disease (GORD)
- Liver related diseases
- Irritable bowel syndrome
- Coeliac disease
Current employment:
- Consultant Gastroenterologist and Interventional Endoscopist, Waikato Hospital, Te Whatu Ora - Health NZ
- Clinical Equity Lead, Waikato - Bowel Screening Program - Te Whatu Ora - Health NZ
- Interventional Endoscopist - Braemar Private Hospital, Waikato
- Clinical Researcher - Westmead Clinical School, Sydney, NSW, Australia
Qualifications:
- MBChB (Otago University)
- MBiomedSci with 1st Class Honors (Auckland University)
- FRACP (Gastroenterology and Hepatology)
Training:
- Advanced Training in Gastroenterology and Hepatology (2019-2021)
- Advanced Interventional Endoscopy Fellowship (Tissue resection, ERCP, EUS) - Westmead Hospital Sydney (2023-2025)
- Honorary Medical Officer, WSLHD, Sydney, Australia (2024-2026)
Research:
(Most recent publications)- Kerrison C, Burgess NG. Updates in the endoscopic management of colorectal polyps. Ind J Gastroenterology 2025
- Gupta S, Bucalau AM, Mandarino FV, Lam B, Figueiredo M, Eisdendrath P, Losurdo G, Sakiris A, Gauci JL, Kerrison C, et al. Oncological impact of universal endoscopic submucosal dissection for large Barrett's cancers. Gut, January 2026.
- Walsh M, Bartholomew K, Koea J, Kerrison C, Bevin N, Heather M. Regional and ethnic projections of gastric cancer incidence in Aotearoa New Zealand to 2045: identifying opportunities for targeted action. N Z Med J. 2026
- Kerrison C, Cassim S, Weilert F, Scott N, Koea J. The narratives of Māori referred for colonoscopy. University of Auckland Library. Masters.
- Gauci JL, Mandarino FV, Kerrison C, et al. Margin thermal ablation eliminates size as a risk factor for recurrence after piecemeal endoscopic mucosal resection of large non-pedunculated colorectal polyps. Gut 2025
- Mandarino FV, O'Sullivan T, Gauci JL, Kerrison C, et al. Impact of margin thermal ablation after cold-forceps avulsion with snare-tip soft coagulation for nonlifting large nonpedunculated colorectal polyps. Endoscopy 2025.
- O'Sullivan T, Cronin O, van Hattem WA, Mandarino FV, Gauci JL, Kerrison C, et al. Cold versus hot snare endoscopic mucosal resection for large (≥15 mm) flat non-pedunculated colorectal polyps: a randomised controlled trial. Gut 2024
Memberships:
- Fellow of the Royal Australasian College of Physicians (RACP)
- New Zealand Society of Gastroenterology (NZSG)
- Hei Ahuru Mowai (Cancer focused National Māori leadership group)
- Co-chair - National Bowel Screening – Māori Network, NZ
