Research
Dr Leong's research interests include clinical drug trials, inflammatory bowel disease epidemiology, biomarker discovery and advanced endoscopic imaging including confocal laser endomicroscopy and panoramic endoscopy. He is widely published in these fields including in the top ranked specialty journal Gastroenterology and Gut. Dr Leong has been awarded prestigious research grants, fellowships and prizes including from the National Health and Medical Research Council (NHMRC) of Australia and Gastroenterological Society of Australia.
"My research aims to find simple, translatable and cost-effective solutions to common gastrointestinal problems and to develop preventative measures or early detection through screening."

Clinical drug trials
Dr Leong is principle investigator for several multi-centre clinical drug trials mostly in inflammatory bowel diseases at Concord and Macquarie University Hospitals. These trials are approved by the Human Research Ethics Committee and certified on clinicaltrials.gov. Please discuss with me if you are interested in participating.
IBD epidemiology
Prof Leong is the current chair of the following research groups or resources:
Sydney IBD Cohort
Persistence in Australian IBD Cohort (PANIC) national registry
IBD in the Asia Pacific region
- consensus guidelines development
PhD/MD/Masters Students
Dr Christian Selinger (MD)
Dr Dorothy Chow (MD)
Dr Yunki Yau (PhD)
Dr Crispin Corte (PhD)
Dr Jeff Chang (PhD)
Dr Viraj Kariyawasam (PhD)
Dr Jo chen (Masters)
Dr Nikola Mitrev (Masters)
Dr Hadis Mirzaei (Masters)
Dr Craig Haifer (PhD)
Dr Brandon Baraty (PhD)
Dr Aviv Pudipeddi (PhD)
Dr Cheng Lee (PhD)
Dr Robyn Laube (PhD)
Dr Gokal Tamilarasan (PhD)
IBD biomarkers
Proteomics and Metabolomics in IBD
IBD endoscopy
Confocal laser endomicroscopy
Leaky gut in inflammatory bowel diseases and controls.
Full Spectrum Endoscopy
and dysplasia (FUSION Study)
Artificial Intelligence: Computer Aided Diagnosis in confocal laser endomicroscopy
Bowel Cancer
SUCCESS Study: Sydney of Colorectal Cancer Screening Study (enrolling) please see your GP
Colonoscopy quality, improving mean adenoma detection rates
IBD patient outcomes
IBD patient outcomes
Entyvio Lengthen Dost Interval Study (ELDIS)
Vedolizumab Immunomodulator Enforced Withdrawal Study (VIEWS)
Quality of life, disability
- validation of Chinese IBDQ
- IBD Disability Index
Pregnancy knowledge
IBD gut microbiome
IBD gut microbiome
Consensus guidelines on faecal microbiota transplantation (FMT)
FMT therapeutics and clinical trials
Consensus guidelines on faecal microbiota transplantation (FMT)
FMT therapeutics and clinical trials
Collaboration with the AIMS group and UNSW
Endoscopy outcomes
Consensus guidelines on faecal microbiota transplantation (FMT)
FMT therapeutics and clinical trials