Dr. Ana Huerta Alardin

Dr. Ana Huerta Alardin was born and raised in Tampico, Mexico.  She earned her medical degree from the Universidad Autonoma de Tamaulipas, Facultad de Medicina, Tampico, Tamaulipas Mexico.  She completed her Internal Medicine residency at Texas Tech University Health Science Center, El Paso, Texas in 2011. She then finished her Gastroenterology and Hepatology  Fellowship at the University of Iowa Hospitals and Clinics, Iowa City, Iowa in 2014.  She worked as a Gastroenterologist at Allen Digestive Health and Cedar Valley Medical Specialists from 2014-2017.  She is Certified with the American Board of Internal Medicine and Gastroenterology.   She will be providing care at our Greeley office location.  She joined Centers for Gastroenterology in 2018.  Se habla Espanol!

Dr. Sean Caufield

Dr. Caufield received his undergraduate degree in Biology from the University of Notre Dame in Notre Dame, Indiana. He is board certified in Internal Medicine and Gastroenterology. He earned his medical degree in 2005 from the Stritch School of Medicine in Loyola, Illinois. Dr. Caufield completed his internship and residency at the Naval Medical Center Portsmouth in Portsmouth, Virginia. He then finished his Gastroenterology Fellowship at the Naval Medical Center in San Diego, CA in 2013. Dr. Caufield served an additional three years in the Navy, concluding his military career as the Director of Endoscopy at the Naval Medical Center in Portsmouth, VA. He is a member of the American College of Gastroenterology and the American Society of Gastrointestinal Endoscopy. Dr. Caufield joined Centers for Gastroenterology in 2016.

Dr. Rand F. Compton

Dr. Compton is a graduate of Poudre High School and Colorado State University. He received his MD from The University of Colorado School of Medicine in 1991. He is board certified in Internal Medicine and Gastroenterology. Dr. Compton was an Internal Medicine Resident from 1991-1994 and a Gastroenterology Fellow from 1994-1997 at the Mayo Clinic, Rochester, Minnesota. He is currently a member of the American College of Physicians, the American College of Gastroenterology, the American Society for Gastrointestinal Endoscopy and the Colorado Medical Society. He joined the Centers for Gastroenterology in 1999.

Dr. Thomas A. Dowgin

Dr. Dowgin sees patients at our Greeley and Fort Collins Offices. He attended Gettysburg College, Gettysburg, Pennsylvania for his undergraduate degree. Dr. Dowgin received his medical degree from New Jersey Medical School, Newark, New Jersey in 1984. He finished his Internship at The National Naval Medical Center, Bethesda Maryland in 1985 and completed Internal Medicine Residency in 1988, and GI Fellowship in 1992, all at Bethesda. He is board certified in Internal Medicine and Gastroenterology. Dr Dowgin is a Fellow of the American College of Physicians, a member of the American Gastroenterological Association, as well as the American Society for Gastrointestinal Endoscopy and the American College of Gastroenterology. Dr. Dowgin was on active duty in the U.S. Navy from 1984-1995. Prior to leaving the Navy, Commander Dowgin was gastroenterology consultant to the Office of the Attending Physician at the U.S. Capitol in Washington, D.C. Dr. Dowgin joined the practice in 2005.

Dr. Rebecca A. Dunphy

After studying for her undergraduate at Wellesley College, Dr. Dunphy received her medical degree from St Louis University School of Medicine in 1996. Dr. Dunphy completed an internship at Barnes-Jewish Hospital, St. Louis Missouri in 1997 after which she completed her Residency and Fellowship in Gastroenterology at the University of Florida, Gainesville, Florida. She is a member of the American Gastroenterological Association and the American College of Gastroenterology. Dr. Dunphy was certified with the American Board of Internal Medicine in 1999, and the American Board of Gastroenterology in 2002. Dr. Dunphy joined the practice in 2003.

Dr. Mark N. Durkan

Dr. Durkan graduated from the National University of Ireland, University College in Dublin in 1993. After an internship at Limerick Regional Hospital in Ireland, Dr. Durkan completed his residency at Saint Josephs Hospital, County Tipperary, Republic of Ireland. He completed his Medicine Residency at the Beth Israel Medical Center , NY between 1986 – 1990. He then completed a fellowship in GI/ Liver at the University of Colorado Health Sciences Center in Denver, 1990 – 2002. He is a member of the American Gastroenterological Association as well as the American College of Gastroenterology. He has been certified with the American Board of Internal Medicine Gastroenterology since November of 2003 and has joined the Centers for Gastroenterology in 2002.

Dr. Daniel D. Hampton

Dr. Hampton received his undergraduate degree from New Mexico State University in Las Cruces, New Mexico. He attended The Ohio State University Medical School graduating in 2004. Dr. Hampton then completed both his Internal Medicine Residency and Fellowship in Gastroenterology at Duke University Medical Center in Durham, North Carolina. Dr. Hampton is a member of the American College of Physicians, American Gastroenterological Association and the American Society of Gastrointestinal Endoscopy. Dr. Hampton joined the practice in 2015.

Dr. Joseph X. Jenkins

Dr. Jenkins studied for his undergraduate as well as for his medical degree at Creighton University, Omaha Nebraska graduating in 1983. He finished his residency at the Medical College of Wisconsin, Milwaukee Wisconsin in 1986. Dr. Jenkins then completed his fellowship at Loyola University Medical Center and Hines Veterans Administration Hospital, Chicago, Illinois in 1988. He is board certified in Internal Medicine and Gastroenterology. He is currently a fellow of the American College of Gastroenterology, and a member of the Colorado Medical Association, American Society for Gastrointestinal Endoscopy and the American College of Physicians. Dr. Jenkins joined the practice in 1994.

Dr. Nicole Kershner

Dr. Kershner received her undergraduate degree from the University of North Carolina at Chapel Hill. She attended Eastern Virginia Medical School in Norfolk, Virginia, graduating in 2008. Dr. Kershner then completed both her Internal Medicine Residency and Fellowship in Gastroenterology, Hepatology, and Nutrition at the University of Louisville Hospital in Louisville, Kentucky. Dr. Kershner is a member of the American College of Physicians, American Gastroenterological Association and the American Society of Gastrointestinal Endoscopy. She is board certified in Internal Medicine and Gastroenterology. Dr. Kershner joined the practice in 2014.

Dr. Daniel Langer

Dr. Langer was raised in Colorado and received his undergraduate degree from Metropolitan State College of Denver in 1996. In 2001, he received his medical degree from the University of Colorado Health Sciences Center and was elected to the Alpha-Omega-Alpha medical honor society. He completed his internal medicine internship and residency, also at the University of Colorado, in 2004. From 2004-2008 he received fellowship training in Gastroenterology and Hepatology at the Mayo Clinic in Rochester, Minnesota. He focused on the study of liver disease and has published several peer-reviewed papers. He received the J. Arnold Bargen award for excellence in research. He then moved back to Colorado to join Centers for Gastroenterology in 2008. He is board certified in Internal Medicine and Gastroenterology. He is a member of the American Gastroenterological Association, American College of Gastroenterology, and the American Society for Gastrointestinal Endoscopy. Dr. Langer joined Centers for Gastroenterology in 2008.

Dr. Crystal North

Dr. Crystal North received her B.S. in Molecular and Cellular Biology from the University of Alaska in Fairbanks. She earned her medical degree from Midwestern University in 2002 and completed her internal medicine residency training in 2005 at Providence St. Vincent Medical Center in Portland, Oregon. She finished her Gastroenterology fellowship training at Midwestern University in Chicago in 2008. Dr. North is board certified in Internal Medicine and Gastroenterology and is a member of the American Gastroenterological Association and the American College of Gastroenterology. In addition to enjoying the full spectrum of Gastroenterology, Dr. North has a particular interest in fecal (bowel) incontinence and, in partnership with Skyline Endoscopy Center, has developed a bowel incontinence clinic, offering a full spectrum of diagnosis and treatment options. Dr. North joined Centers for Gastroenterology in September 2009.

Dr. Stephen Sears

Dr. Stephen Sears received his BS from James Madison University in Harrisonburg, VA. He earned his medical degree in 1995 from the Uniformed Services University of the Health Sciences in Bethesda, MD. Dr Sears completed his internship and residency at Eisenhower Army Medical Center in Augusta, GA. He then finished his Gastroenterology Fellowship at Brooke Army Medical Center in San Antonio, TX in 2001. Dr. Sears served an additional seven years in the Army, concluding his military career as Chief of Gastroenterology at Madigan Army Medical Center in Tacoma, WA. He is a member of the American College of Gastroenterology and the American Society of Gastrointestinal Endoscopy. He is board certified in Internal Medicine and Gastroenterology. Dr. Sears joined Centers for Gastroenterology in 2008.

Dr. Lewis Strong

Lewis Strong, M.D., has been practicing gastroenterology in Loveland since 1991. Dr. Strong is Board Certified in Gastroenterology. He recertified in 2001. Dr. Strong earned his medical degree from Case Western Reserve University School of Medicine in Cleveland, OH. He completed his residency program at the University Hospitals of Cleveland. He received his Fellowship training in Gastroenterology from Case Western Reserve University School of Medicine. He has a particular interest in digestive diseases, diseases of the liver and colon cancer screening. In addition to keeping up with his busy medical practice, Dr. Strong enjoys bicycling, snow skiing and woodworking. He also speaks fluent French. Dr Strong joined the Centers for Gastroenterology in 2007.

Nurse Practitioner/PA-C

Brian Cronk, PA-C

After earning his Masters of Public Health from Loma Linda University in California in 1996, Brian attended the Primary Care Physician Assistant Program at Western University of Health Sciences in Pomona, CA. His prior medical setting experience includes family practice, urgent care, and internal medicine. He has a special interest in treating patients diagnosed with hepatitis. Brian joined Centers for Gastroenterology in 2007.

Tara Jewell, DNP, NP-C

Tara is a Doctor of Nursing Practice as well as a board certified Adult – Gerontology Nurse Practitioner with experience working with acute and chronically ill patients. Her prior medical experience includes caring for patients in the intensive care, cardiology, and oncology units in the hospital; as well as caring for patients in a gastroenterology practice. Tara earned her bachelor’s degree in nursing from the University of Iowa in 2004. While working as a registered nurse she obtained her Doctor of Nursing Practice at the University of Iowa in 2013. She is a member of the American Association of Nurse Practitioners. She joined the Centers for Gastroenterology in 2015.

Sharon Margraf, BSN, MSN, NP

Sharon earned both her BSN and MSN from Loyola University in Chicago. She received her Adult-Gerontology Primary Care Nurse Practitioner Certification in 2013. Sharon has worked in gastroenterology at Loyola University Medical Center, Rush-Presbyterian St. Luke’s Medical Center, and at the University of Chicago Medical Center. Her prior medical experience also includes work in cancer care, hematology and general surgery. Sharon has made presentations on “Advanced Provider Perspectives: Treatment for Inflammatory Bowel Diseases, Best Practices in IBD Management, and Living with a J-Pouch for the Crohn’s and Colitis Foundation of America. Sharon joined Centers for Gastroenterology in 2016.

Colin E. Strack, PA-C, MMS

Colin received his BS from Colorado State University in Fort Collins, CO. He earned his master’s in medical science from Saint Frances University in Loretto, PA and went on to earn his Physician Assistant Certification from Red Rocks Community College in Lakewood, CO. His prior medical experience includes working as a Certified Nursing Assistant at Poudre Valley Hospital and working as a PA for Front Range Gastroenterology and Colorado Endoscopy Centers, LLC. He enjoys cycling, hiking, and computer science. Colin joined Centers for Gastroenterology in 2017.