GTA Endoscopists

GTA Endoscopy Services offers the expertise and experience of our staff of specialists in endoscopic techniques. Staffed primarily by doctors affiliated with Rouge Valley Centenary Hospital, we provide more than screening and diagnosis. Our team of surgeons can provide you with the latest approaches, including minimally invasive surgery for treating colon cancer, if this is ever needed. All doctors at GTA Endoscopy Services Inc. are certified by the Royal College of Physicians & Surgeons of Canada.

Endoscopist Profiles:

Dr. Tom Anderson

Dr. Tom Anderson

Graduated from the University of Toronto with his M.D. in 1981, he completed his postgraduate training in General Surgery (Gallee Course) at the University of Toronto. Dr. Tom Anderson has been on staff at Rouge Valley Centenary Hospital since 1987.

Dr. Ulana Kawun

Dr. Ulana Kawun

Completed a five year training in General Surgery at the University of Toronto. She continued with a one year fellowship in Laparoscopic Colorectal Surgery in Philadelphia which focused on the treatment of colorectal cancer and benign colorectal diseases using a minimally invasive approach. She has been on staff at Rouge Valley Centenary since 2005.

Dr. Naresh Mohan

Dr. Naresh Mohan

It is the medical director of GTA Endoscopy Services Inc. as well as a staff endoscopist at GTA Endoscopy. He completed his undergraduate medical training in Jamaica and came to Canada for his surgical training at the University of Toronto. He has been on staff at Rouge Valley Centenary Hospital since 1993. He is also actively involved in Medical Administration and is the current Chief of Staff of the Rouge Valley Health System.

Dr. Arvind Nanda

Dr. Arvind Nanda

Completed his medical training at the University of Toronto as part of the combined MD/ Ph.D. Program, graduating in 1998 with both an MD and a Ph.D. degree. He then went on to complete his General Surgery training by 2003 and joined Rouge Valley Centenary in July 2004 after working as a General Surgeon in remote areas of Northern Ontario and the Northwest Territories. Dr. Nanda’s clinical focus includes endoscopy, general surgery (thyroid, breast, gallbladder, hernia), with a special interest in cancer surgery of the breast and laparoscopic/minimally invasive surgery of the colon and rectum.

Dr. Nazareno

Dr. Nazareno

Received his B.Sc. from the University of Toronto, and earned his M.D. at the University of Calgary. Most recently, Dr. Nazareno worked as an Adjunct Professor at the University of Western Ontario, where he also completed his training in Gastroenterology and Internal Medicine. He has special interests in Inflammatory Bowel Disease, Esophageal Motility, and Reflux. Dr. Nazareno is one of the newest additions to the Internal Medicine Staff at Rouge Valley Health System.

Dr. Rowena Almeida

Dr. Rowena Almeida

Dr. Almeida earned her medical degree with honors from the Royal College of Surgeons in Ireland. She completed her internal medicine residency at Queen’s University, Kingston, Canada and thereafter pursued her gastroenterology fellowship at the University of Toronto, Canada. She completed an advanced clinical hepatology fellowship at the Toronto Centre for Liver Disease, University Health Network and Sinai Health Systems. Dr. Almeida joined the Scarborough Hospital – Centenary Site hospital as associate staff in January 2019.

Dr. Grant Chen

Dr. Grant Chen

Dr. Grant Chen completed medical school at the University of Toronto in 2000 before moving on to post-graduate training in Internal Medicine at the University of Western Ontario, where he was a Chief Medical Resident and Gastroenterology at Dalhousie University. He returned to Toronto to do a clinical fellowship in Inflammatory Bowel Disease with Dr. Fred Saibil at Sunnybrook Health Sciences Centre. He has worked as a Clinical Associate at Sunnybrook and since 2008, has been on staff at The Scarborough Hospital - General Division.


Dr. Chen's clinical interests include inflammatory bowel disease and hereditary colorectal cancer syndromes although his practice encompasses general gastroenterology and hepatology. He has a particular interest in medical education and completed the Master Teacher Program at the University of Toronto. He is currently a Lecturer in the Department of Medicine at the University of Toronto as well as a tutor and site coordinator for the first-year Art and Science of Clinical Medicine (ASCM) course at Sunnybrook.

Dr. Wesley Leung

Dr. Wesley Leung

Dr. Wesley leung completed his internal medicine and GI training at UofT graduating in 2011. He also trained as a therapeutic endoscopist with an interest in pancreatobiliary disorders at Indiana University and completed a 1 year program in endoscopic oncology at the University of Chicago.

Dr. Vishal Patel

Dr. Vishal Patel

Dr. Vishal Patel is a board certified gastroenterologist, with additional training in therapeutic endoscopy. He is affiliated with North York General Hospital. Dr. Patel received his medical degree from the University of Toronto, and then attended the University of Western Ontario for his internal medicine and gastroenterology residencies. He also completed a clinical pharmacology fellowship during his residency.

All endoscopists who use the facilities of GTA Endoscopy Services Inc.:
  • possess a valid certificate of registration from the College of Physicians and Surgeons of Ontario or Certification with the Canadian Association of Gastroenterology
  • hold certification from the Royal College of Physicians and Surgeons of Canada, which confirms training and specialty designation to perform the procedures acceptable at GTA Endoscopy Services Inc.
  • are in good standing with the Royal College of Physicians and Surgeons of Canada
  • are licensed by the College of Physicians and Surgeons of Ontario and be in good standing with the professional body
  • are on active staff holding current and active privileges at a Greater Toronto Area Hospital, which support similar procedures
  • have active hospital admitting privileges at a Greater Toronto Area hospital
  • maintain CMPA insurance