Mark Pimentel, MD
Disclosures: Royalty-Bausch Health|Receipt of Intellectual Property Rights/Patent Holder-Cedars has a licensing agreement with Salix,Naia,Sythctic Biologics, and Gemelli Biotech|Consulting Fee-Salix, Naia Pharmaceuticals, Synthetic Biologics, Shire, US Medical|Speakers Bureau-Salix|Contracted Research-Bausch Health|Ownership Interest-Naia Pharmaceuticals, Synthetic Biologics|Currently on the board of Gemelli Biotech-Gemelli Biotech
Christine L




Mark Pimentel, M.D., FRCP(C)

Executive Director, Medically Associated Science and Technology (MAST) Program

Professor of Medicine, Geffen School of Medicine

Cedars-Sinai Medical Center 

Los Angeles, California 


Mark Pimentel, M.D., is Professor of Medicine, Geffen School of Medicine and Associate Professor at Cedars-Sinai Medical Center in Los Angeles, California.  Dr. Pimentel completed 3 years of an undergraduate degree in honors microbiology and biochemistry at the University of Manitoba, Canada. This was followed by his medical degree, and his BSc (Med) from the University of Manitoba Health Sciences Center in Winnipeg, Manitoba, Canada, where he also completed a residency in internal medicine. His medical training includes a fellowship in gastroenterology at the UCLA Affiliated Training Program. Active in research, Dr. Pimentel has served as a principal investigator or co-investigator for numerous basic science, translational and clinical studies in such areas as IBS, and the relationship between gut flora composition and human disease. His work has been published in the New England Journal of Medicine, Annals of Internal Medicine, American Journal of Physiology, American Journal of Medicine, American Journal of Gastroenterology and Digestive Diseases and Sciences, among others. Dr. Pimentel has been invited to present his work at meetings, grand rounds, and advisory boards in the United States and Internationally. He is diplomate of the American Board of Internal Medicine (Gastroenterology) and a fellow of the Royal College of Physicians and Surgeons of Canada. Dr. Pimentel is also a member of several medical associations including the American Gastroenterological Association, the American College of Gastroenterology, and the American Neurogastroenterology and Motility Society. 


A few of Dr. Pimentel’s most significant accomplishments include:

  1. The discovery of rifaximin as a treatment for irritable bowel syndrome (IBS)
  2. He developed the first blood test for IBS on the basis of IBS being derived from acute gastroenteritis
  3. Described the association between IBS and bacterial overgrowth which forms the basis for microbiome therapies in this condition
  4. Uncovered the methanogen (M. smithii) as an agent for causing constipation in humans.
  5. Discovered the use of lovastatin as a microbiome treatment for constipation on the basis of inhibiting methane production by methanogens