Felix W. Leung, MD, a native of Hong Kong, began his post high school education in the United States in 1970. He did his undergraduate work at Yale College and received his degree of Doctor of Medicine in 1978 from Yale Medical School. Since then he has maintained a longstanding association with the University of California at Los Angeles. He did his medicine training at the UCLA-Wadsworth VAMC; continued on with the UCLA-Wadsworth Gastroenterology Fellowship. He completed post-doctoral fellowship training at the Center for Ulcer Research and Education (CURE) supported by an ASGE Endoscopic Career Development Award. In 1986 he began his UCLA faculty appointment at the Sepulveda VAMC. He is currently affiliated with the Section of Gastroenterology, Sepulveda Ambulatory Care Center and Nursing Home and the West Los Angeles VAMC, VA Greater Los Angeles Healthcare System and is Professor of Medicine in Residence at the David Geffen School of Medicine at UCLA.
He has received research support from Department of Veterans Affairs, California Tobacco-Related Diseases Research Program, Smokeless Tobacco Research Council, Inc., American Society for Gastrointestinal Endoscopy, American Gastroenterological Association, American Digestive Health Foundation, American College of Gastroenterology, National Institute of Health and several pharmaceutical companies and industry sources.
He has a broad range of interests - experimental and endoscopic assessment of gastrointestinal blood flow, management of fecal incontinence and most recently the water exchange method for colonoscopy. In the mid 2000s the need to develop a less painful method for colonoscopy without the use of air insufflations led him and his research team to modify the established water immersion method to develop the novel water exchange method for colonoscopy. Subsequent reviews of randomized controlled trial published in Journal of Interventional Gastroenterology (JIG) confirmed that water immersion and water exchange both significantly reduce colonoscopy pain; water exchange may be superior to water immersion in reducing discomfort and enhancing adenoma detection (particularly in the proximal colon). The major distinction in the nuances of the methods is the removal of the infused water predominantly during insertion in water exchange vs. during withdrawal in water immersion. In the context of conventional colonoscopy failing to reduce colon cancer mortality in the proximal colon as effectively as in the distal colon, the serendipitous result with the water exchange method is provocative. Excitement over the new developments is definitely warranted and JIG has played a critical role in disseminating the information. In the past year he has conducted a number of site visits to show interested colleagues the nuances of the novel method. He hopes to set up a study to determine if the enhanced detection of adenomas by the water exchange method translates into improved efficacy of screening colonoscopy.