Medical Advisory Board

Lawrence B. Cohen, MD
Piet de Groen, MD
Nicolas Hoepffner, MD
Felix W. Leung, MD
Douglas K. Rex, MD
Thomas Rösch, MD

Lawrence B. Cohen, MD

Dr. Cohen is an Associate Clinical Professor and Director of the Gastrointestinal Motility Unit at The Mount Sinai Hospital New York. He graduated with highest honors from Hahnemann Medical College, and completed his medical residency and fellowship in gastroenterology at The Mount Sinai Hospital. He has authored more than thirty articles, as well as a textbook of endoscopy. Dr. Cohen's research activities for the past fifteen years have focused on esophageal diseases and swallowing disorders, and he lectures throughout the United States on these topics.

Piet de Groen, MD

Dr. Piet de Groen is Professor of Medicine at Mayo Clinic College of Medicine with a primary appointment in Gastroenterology and joint appointment in Health Sciences Research with an interest in biomedical informatics at Mayo Clinic in Rochester, Minnesota. His clinical practice and research interests are focused on the diagnosis and treatment of patients with primary liver cancers and the endoscopic assessment and treatment of colon lesions including polyps and cancer. He has led the development of web-based databases and applications for the Mayo Clinic Comprehensive Cancer Center in Rochester and was the Program Director of the Mayo Clinic/IBM Computational Biology Collaboration from 2002-2007. Under his leadership, a comprehensive prototype system (the Mayo Clinic Life Sciences System) was developed to facilitate access to and interpretation of clinical, genomic and proteomic data.

Nicolas Hoepffner, MD

Dr. Hoepffner is a specialist for internal medicine (gastroenterology, intensive care). He is practicing at the Centrum Gastroenterologie Bethanien, the largest single-specialty ambulatory surgery center in Frankfurt.

Felix W. Leung, MD

Dr. Leung is a Professor of Medicine at David Geffen School of Medicine at the University of California at Los Angeles. He is a proponent of minimizing the burden of colorectal cancer screening on patients. He has adopted the role of a strong patient advocate and has proposed the use of various options (patient choices) of colonoscopy without routine sedations in the United States. His research in endoscopic methods to minimize discomfort during scheduled, unsedated colonoscopy is supported by the American College of Gastroenterology. He is currently a member of the Editorial Board of Gastrointestinal Endoscopy and a Fellow of the American College of Gastroenterology.

Douglas K. Rex, MD

Dr. Rex is a Professor of Medicine at Indiana University School of Medicine and Director of Endoscopy at Indiana University Hospital in Indianapolis. He is a full-time clinical gastroenterologist at Indiana University Hospital and personally performs about 2,500 endoscopic procedures per year. He co-authored the colorectal cancer screening recommendations of the American College of Gastroenterology. He is currently the Chairman of the U.S. Multi-Society (ACG, ASGE, AGA, ACP-ASIM) Task Force on Colorectal Cancer and the former President of the American College of Gastroenterology.

Thomas Rösch, MD

Thomas Rösch is the Director of the Clinic for Interdisciplinary Endoscopy at the University Hospital Hamburg-Eppendorf (Germany). His specialty is gastroenterology. Dr. Rösch was certified as a specialist in internal medicine and gastroenterology in 1995. He has performed a number of studies on various topics in gastrointestinal endoscopy published in high-ranking journals and is currently Editor in Chief of the journal Endoscopy, one of the two major international journals in this area.