Dr Kostalas relocated with his family to Port Macquarie in 2013. His education includes an undergraduate medical degree, a masters degree in medicine (clinical epidemiology), a masters degree in science from the University of Oxford (in evidence based health care and medical statistics), and a fellowship of the Royal Australasian College of Physicians.

Stuart undertook his training across a variety of hospitals in NSW. Importantly, he has continued to train at leading centres all over the world (Japan, France, USA, Austria, and the Netherlands). He regularly travels overseas to train with international experts, to refine his endoscopic and clinical knowledge, and to make sure his skills and knowledge are both current and relevant.

Recognising the Japanese mastery of interventional endoscopy, he decided to bring Prof Noriya Uedo to Port Macquarie to supervise and teach advanced endoscopic procedures (Uedo visit). In early 2018 he was joined by Prof Toyonaga, one of the world's leading experts in endoscopic cancer resection (Toyonaga 2018). He continued this tradition with a further educational visit by Prof Toyonaga in 2019 (Toyonaga 2019). In 2020 he conducted an advanced endoscopy "masterclass" for other Gastroenterologists with Prof Toyonaga in Port Macquarie (Toyonaga 2020).

Dr Kostalas is interested and experienced (having performed over 10,000 colonoscopies) in the breadth of luminal gastroenterology; all aspects of endoscopy, the diagnosis and management of inflammatory bowel disease and preventing bowel cancer (colorectal cancer screening). During his career he has won numerous teaching awards including the “Dean’s award for excellence in teaching” twice. Dr Kostalas was nominated for the "Brian Yeo Best Teacher Award" at the University of New South Wales in 2012. In the same year he won the Wiley Blackwell Publishing Award for "Clinical Excellence in Adult Medicine" from the Royal Australasian College of Physicans.

Dr Kostalas pursues current evidenced based practice in Gastroenterology and Hepatology. As part of his commitment to ongoing learning and the pursuit of best practice he is a member of many international GI societies. Dr Kostalas is a (Conjoint) Senior Lecturer at the University of New South Wales. He is the Gastroenterology representative on the Medical Advisory Committee at Port Macquarie Private Hospital, served as a working group member on the NSW scope of clinical practice in Gastroenterology and Hepatology and is the primary supervisor of Gastroenterology Advanced Trainees at Port Macquarie.

Clinical interests

Endoscopic resection of early gastrointestional neoplasia / Full thickness resection of gastrointestional tract lesions / Advanced interventional Endoscopy

Quality in Endoscopy

Serrated Polyps / Serrated Polyposis Syndrome (SPS)

Colorectal cancer screening and prevention

Optical diagnosis and monitoring of gastrointestional epithelial lesions


Underpinning our core value of excellent patient care, Port Macquarie Gastroenterology (PMQ Gastro) recognises that the best medical care is delivered by a team. Dr Kostalas works with his colleague Dr Sundaralingham (PMQ Gastro's pancreatobiliary expert), and Clyte (PMQ Gastro's specialised IBD nurse) along with a carefully chosen group of outstanding Anaethetists, Nurses, Radiologists and Surgeons. The goal of his team is to provide exceptional, current, and relevant care. Outcomes cannot be guaranteed, however when referral is necessary, we refer to other experts who we know share the same vision for our patients. Dr Kostalas and his team look forward to delivering the best medical care to you and your family.


MBBS (Hons1)

MM (Clin Epi)

MSc (Oxon)


Academic appointments

Conjoint senior lecturer - University of New South Wales 


GESA conjoint committee recognised for training in Gastroscopy (Adult), Colonoscopy (Adult), and Endoscopic Retrograde Cholangiopancreatography (ERCP)

GESA Colonoscopy Recertification in Adult Colonoscopy 2016 – 2019

GESA Colonoscopy Recertification in Adult Colonoscopy 2019 – 2022