Our Team

The following gastroenterologists are affiliated with the TDDA and function as Investigators for the various ongoing clinical studies:

Jeffrey L. Axler

Jeffrey L. Axler, MD., FRCP(C)
Gastroenterologist, William Osler Health Centre - Etobicoke Hospital Campus
Lecturer at University of Toronto

Dr. Jeff Axler has been in clinical Gastroenterology practice in Toronto for over 30 years. He has been the Head the GI division at the Etobicoke General and William Osler Hospitals. He was a clinical advisor to Cancer Care Ontario to start the Ontario Colon Cancer screening program, now called Colon Check. He collaborated on and co-wrote the initial standards and guidelines for physicians doing colonoscopy in Ontario. He was the head of the provincial GI doctors’ organization, Ontario Association of Gastroenterology as President, and has served on its Board of Directors for 12 years. He was the Head of the OMA Section of Gastroenterology for 4 years.

He is an original founding member of Toronto Digestive Disease Associates Inc., (TDDA), and is a member of the Executive of this company. He has been a Principal Investigator for TDDA for many successful clinical trials over the past 12 years. Some of the trials were internationally acclaimed, and he has presented this data throughout North America and Europe at international research meetings. He is a co-author of papers in journals of international importance, including the New England Journal of Medicine.

He continues to practice in downtown Toronto, as the Head of Gastroenterology and Endoscopy at The Medcan Clinic, a private health clinic in Canada. He also practices in a community setting in northwest Toronto, affiliated with Etobicoke General Hospital. He was appointed as a peer reviewer by the College of Physicians and Surgeons, (CPSO) and as a Site inspector for Out of Hospital Premises for the CPSO. He is a lecturer at the University of Toronto, and teaches GI residents and fellows about community GI practices. He has a busy clinical GI practice, focusing on Inflammatory Bowel Disease.

David C. S. Ford

David C. S. Ford, MD., M.Sc., FRCP (C)
Gastroenterologist, William Osler Health Centre - Etobicoke Hospital Campus

Dr. David Ford graduated from McMaster University in 1995 with his medical degree and completed his Internal Medicine qualifications in 1998. He further specialized in Gastroenterology, with additional training in ERCP. Prior to obtaining his medical degree, Dr. Ford completed his Bachelor of Science degree in Biochemistry and a Master of Science degree in Immunology. Dr. Ford's current position is Site Chief of Gastroenterology at the William Osler Health Centre, Etobicoke Campus. Dr. Ford is the Vice President of the Vaughan Endoscopy Clinic. Dr. Ford is a Vice President, a member of our Executive Committee and a founding partner in the Toronto Digestive Disease Associates Inc., (TDDA), clinical research group. Dr. Ford is one of TDDA’s Principal Investigators, (PI), tasked with leading an assortment of GI clinical research trials. Dr. Ford also acts as a Sub-investigator in support of our other PIs leading our GI clinical research studies.

Dr. Ford is a frequent guest speaker on behalf of various groups in the pharmaceutical industry where he provides presentations to physicians covering many GI issues. He has been published in peer reviewed Journals on matters and studies related to his work at TDDA.”

Michael I. Gould

Michael I. Gould, MD., FRCP(C)
Gastroenterologist, William Osler Health Centre - Etobicoke Hospital Campus
Assistant Professor at the University of Toronto.

Dr. Michael Gould recently completed a 3-year term as the Provincial Endoscopy and QBP Lead for Cancer Care Ontario. He is the President and Medical Director of the Vaughan Endoscopy Clinic in Vaughan. He is a Vice President, a member of our Executive Committee and a founding member in the Toronto Digestive Disease Associates Inc., (TDDA), clinical research group. Dr. Gould is one of TDDA’s Principal Investigators, (PI), tasked with leading an assortment of GI clinical research trials. Dr. Gould also acts as a Sub-investigator in support of our other PIs leading our GI clinical research studies.

He is a Past Chief of Medicine of the William Osler Health Centre. He is a past President and one of the founders, of the Ontario Association of Gastroenterology, and currently sits on the OAG board of directors. He is a board member of the Canadian Digestive Health Foundation, and the Israel Cancer Research Fund.

He has been a member of numerous Colonoscopy Guideline committees at the national and provincial levels. He has been extensively involved in the colonoscopy quality agenda at all levels and has contributed extensively to many of the published Canadian and provincial guidelines.

Susan Greenbloom

Susan Greenbloom, MD., FRCP(C)
Gastroenterologist, William Osler Health Centre - Etobicoke Hospital Campus

Dr. Susan Greenbloom graduated from medical school at University of Toronto and completed her Internal Medicine and Gastroenterology specialization at U of T as well. She has been practicing as a gastroenterologist since 1995 and is an active staff member of the William Osler Health Centre, Etobicoke Campus. Dr. Greenbloom has a large gastroenterology practice, including hepatitis expertise due to her Hepatology fellowship at University of Toronto. Dr. Greenbloom a founding member in the Toronto Digestive Disease Associates Inc., (TDDA), clinical research group. Dr. Greenbloom is one of TDDA’s Principal Investigators, (PI), tasked with leading an assortment of GI clinical research trials. Dr. Greenbloom also acts as a Sub-investigator in support of our other PIs leading our GI clinical research studies.

David A. Kreaden

David A. Kreaden, MD., FRCP(C)
Gastroenterologist, Humber River Regional Hospital

Dr. David Kreaden attended University of Toronto Medical School and graduated in 1973 and completed fellowship training in internal medicine and gastroenterology in 1977. Dr. Kreaden was appointed to the department of internal medicine at Northwestern Hospital where he established the division of gastroenterology and was chief until the hospital merged into the Humber River Regional Hospital. Dr. Kreaden is presently staff gastroenterologist and has been at Humber River Regional Hospital since 1998. Presently in addition to luminal gastroenterology and liver, he has an interest in swallowing disorders and heads the motility department at Humber River Hospital. Dr. Kreaden is a member in Toronto Digestive Disease Associates Inc., (TDDA), and is a Sub-investigator in support of our Principal Investigators leading our many GI clinical research studies. Dr. Kreaden is also the Chairman of the Toronto West "Gut Club."

Eric W.H. Leong

Eric W.H. Leong, MD., FRCP(C)
Gastroenterologist, Humber River Regional Hospital

Dr. Leong graduated from The Johns Hopkins University with a Bachelor of Arts degree in Molecular Biology and French Literature in 1989. He subsequently obtained his medical degree at the University of Toronto in 1993 and completed his Internal Medicine residency at U of T. During his Chief Medical Residency and while working as a Clinical Assistant in Gastroenterology at Toronto Western and Toronto General Hospitals, his research focused on bone density and depression in patients with primary biliary cirrhosis. Dr. Leong specialized in Gastroenterology and Hepatology during his fellowship at Stanford University and received training in ERCP and EUS. He is an active staff member at Humber River Regional Hospital. Dr. Leong is a member in Toronto Digestive Disease Associates Inc., (TDDA), and is a Sub-investigator in support of our Principal Investigators leading our many GI clinical research studies.

Michael Jerry Ostro

Michael Jerry Ostro, MD., FRCPC)
Gastroenterologist, Credit Valley Hospital

Dr. Ostro graduated from medical school at University of Toronto in 1979. He also completed his Internal Medicine and Gastroenterology Residencies at U. of T. He did a Research Fellowship in Inflammatory Bowel Disease and acid-suppression therapy. Dr. Ostro is currently active staff as a Gastroenterologist at The Credit Valley Hospital in Mississauga. He is a past Director of Credit Valley Digestive Disease Group. Dr. Ostro is a member in the Toronto Digestive Disease Associates Inc., (TDDA), clinical research group. Dr. Ostro is one of TDDA’s Principal Investigators, (PI), tasked with leading an assortment of GI clinical research trials. Dr. Ostro also acts as a Sub-investigator in support of our other PIs leading our GI clinical research studies.

Theadore W. Ptak

Theadore W. Ptak, MD., FRCP(C), FACP
Gastroenterologist, Humber River Regional Hospital

Dr. Ted Ptak graduated from medical school at the University of Ottawa in 1963 and in Internal Medicine at the University of Toronto in 1968. He followed that up with a Fellowship in Gastroenterology at the University of Chicago (1968-1971). He was the past president of the Ontario Association of Gastroenterologist (2004-2006). Dr. Ptak was the former chief of Medicine at York Finch General Hospital and Humber River Hospital. He is the present Head of Gastroenterology and Endoscopy at Humber River Hospital. Dr. Ptak has a special interest in Therapeutic ERCP, Hepatology, and Endoscopic Ultrasound. He introduced ERCP and EUS to Ontario. Dr. Ptak is the President, a member of our Executive Committee and a founding member in the Toronto Digestive Disease Associates Inc., (TDDA), clinical research group. Dr. Ptak is one of TDDA’s Principal Investigators, (PI), tasked with leading an assortment of GI clinical research trials. Dr. Ptak also acts as a Sub-investigator in support of our other PIs leading our GI clinical research studies.

Vinod Puri

Vinod Puri, MD., FRCP(C)
Gastroenterologist, William Osler Health Centre - Brampton Memorial Hospital Campus

Dr. Vinod Puri is a Gastroenterologist and Internist working at the Brampton Site of William Osler Health Centre. He has been working in the Brampton community for 17 years and was previously on staff at Peel Memorial Hospital. Prior to that, he worked in Dixon, Illinois for one year.

Dr. Puri attended Queen's Medical School and graduated in 1992. He then did his internal medicine residency at the University of Toronto and his Gastroenterology fellowship at McGill University. He completed his Gastroenterology training in 1997 and became board certified in Gastroenterology in both Canada and the US the same year.

He co-founded Scopeclinic, an out of hospital endoscopy facility that places an emphasis on a patient centred experience when having a colonoscopy. He is a passionate proponent of colon cancer awareness and prevention and has appeared on Breakfast Television several times to help people understand the benefits of screening colonoscopy as well as to help calm their fears about this test. He is also a founding member of the Toronto Digestive Disease Associates Inc., (TDDA), clinical research group and is a Sub-investigator in support of our Principal Investigators leading our many GI clinical research studies.

Lee S. Roth

Lee S. Roth , MD., FRCP(C)
Gastroenterologist

Dr. Lee Roth completed his medical training at Western University in 2005 and stayed in London, Ontario for his residency in Internal Medicine and fellowship in Gastroenterology. He achieved a Masters of Science in Clinical Epidemiology at McMaster University, where his interest lay in inflammatory bowel disease. He holds certification from the Royal College of Physicians and Surgeons of Canada in Internal Medicine and Gastroenterology, and is Board Certified in Internal Medicine and Gastroenterology by the American Board of Internal Medicine. He has published widely and in such journals as the American Journal of Gastroenterology, World Journal of Gastroenterology and Inflammatory Bowel Disease, and has carried out a Cochrane Systematic Review. He is currently a practicing community gastroenterologist, utilizing both outpatient clinics and inpatient endoscopy facilities across the west end of the GTA. Dr. Roth is an associate member of Toronto Digestive Disease Associates Inc., (TDDA), and is a Sub-investigator in support of our Principal Investigators leading our many clinical GI research studies.

Rajiv Sethi

Rajiv Sethi, MD., FRCP(C)
Gastroenterologist, William Osler Health Centre - Etobicoke Hospital Campus

Dr. Rajiv Sethi specializes in Gastroenterology. He completed his undergraduate studies at the University of Toronto. He obtained his medical degree from the University of Toronto in 1992. After practicing as a family doctor in Toronto, he completed his specialty training in Internal Medicine at Jacobi Medical Center in New York in 2001. He completed his fellowship in Gastroenterology at the University of Texas Southwestern in Dallas in 2004. He has been on staff at Toronto East General Hospital and Presbyterian Hospital of Plano. He joined the William Osler Health Centre in 2008 as a Gastroenterologist and is currently at the Etobicoke site. Dr. Sethi is a member in the Toronto Digestive Disease Associates Inc., (TDDA), and is a Sub-investigator in support of our Principal Investigators leading our many GI clinical research studies.

Jonathon Springer

Jonathon Springer, MD., FRCP(C)
Gastroenterologist, St. Joseph's Health Centre

Dr. Jonathon Springer graduated from medical school in 1994 and completed his Internal Medicine (1998) and Gastroenterology (1999) specialist training at University of Toronto. He did a therapeutic endoscopy fellowship in Calgary in 1999 and is currently the chief of GI and chair of the endoscopy committee at St. Joseph's Health Centre. Dr. Springer is a community representative on the U of T gastroenterology education training committee and teaches GI residents endoscopy. Dr. Springer is a member of the Toronto Digestive Disease Associates Inc., (TDDA), and is a Sub-investigator in support of our Principal Investigators leading our many GI clinical research studies.

Mission Statement

Our Mission is to deliver high quality clinical trial services to our clients in the pharmaceutical industry while providing access to new and innovative treatments for our patients.


Our Team