Our Staff

All professionals at Northern New Mexico Gastroenterology maintain the highest levels of accreditation and pursue ongoing education to stay abreast of the latest trends in the medical field. Read on to learn more about our staff's experience and training.

David B. Hoverson, M.D.

Specialty: Gastroenterology
Dr. David Hoverson attended medical school at University of New Mexico and then completed a Residency at University of Wisconsin and a Fellowship at University of Colorado Health Sciences Center. He is Board Certified in Internal Medicine and Gastroenterology. He is a member of the American Gastroenterology Association, the American College of Physicians and the New Mexico Medical Society.

 

Cornelius P. Dooley, M.D., F.A.C.G., F.A.G.A.

Specialty: Gastroenterology
Dr. Cornelius Dooley attended University College Dublin School of Medicine for his M.B., B.Ch. and B.A.O. degrees. He completed Internships at Mater Misericordiae Hospital in Dublin, Ireland, and L.A. County-U.S.C. Medical Center in Los Angeles, where he also served as Research Scholar and Fellow in the Section of Gastroenterology. He was awarded his medical degree by thesis from National University of Ireland, and he is Board Certified in Internal Medicine and Gastroenterology. He is a fellow of the American College of Gastroenterology and the American Gastroenterological Association. He is a member of the American College of Physicians and the New Mexico Medical Society.

 

Patrick G. Quinn, M.D., F.A.C.P., F.A.G.A., F.A.S.G.E.

Specialty: Gastroenterology
Dr. Patrick Quinn graduated from Case Western Reserve University School of Medicine with his medical degree. He completed an Internship and Residency at Yale-New Haven Hospital and then a Gastroenterology Fellowship at Mt. Sinai Medical Center. He also did an Advanced Therapeutic Endoscopy Fellowship at Thomas Jefferson University Hospital in Philadelphia. He is a fellow of the American College of Physicians, the American Gastroenterological Association and the American Society for Gastrointestinal Endoscopy. He is a member of the American Association for the Study of Liver Diseases, among other organizations. He is board certified in Internal Medicine and Gastroenterology. 

 

Ricardo Calzada, M.D., F.A.C.G.

Specialty: Gastroenterology
Dr. Ricardo Calzada received his M.D. degree from University of San Carlos de Borromeo School of Medicine. He then completed a Rotating Internship and Internal Medicine Residency at Roosevelt Hospital in Guatemala City, Guatemala, and then did another Internal Medicine Residency and Gastroenterology Fellowship at Wayne State University in Detroit. Dr. Calzada has his New Mexico medical license and is Board Certified in Internal Medicine and Gastroenterology. He is a fellow of the American College of Gastroenterology, and he is a member of the American Association of Physicians and Surgeons, American Gastroenterological Association, American Medical Association, and the New Mexico Medical Society.

 

Bradley B. Rowberry. M.D.

Dr. Bradley Rowberry graduated from Tulane University School of Medicine with his medical degree. He completed internship and residency in Internal Medicine, as well as gastroenterology fellowship at the University of Texas in San Antonio Texas. Dr. Rowberry is a member of the American College of Physicians, the American Society of Internal Medicine, the New Mexico Medical Society, and Los Alamos Medical Society.

 

Alejandra I. Castillo-Roth, M.D.

Specialty: Gastroenterology
Dr. Alejandra Castillo-Roth received her medical degree from Luis Razetti Medical School at Central University of Venezuela. She then served as Intern, Resident and then Chief Resident at State University of New York. She also served as a Fellow and Research Fellow in the Division of Digestive Disease and Hepatology there. She completed an Advanced Endoscopy Fellowship at Duke University Medical Center in North Carolina. Dr. Castillo-Roth is Board Certified in Internal Medicine and Gastroenterology and is a member of the American Gastroenterology Association, American Society of Gastrointestinal Endoscopy, American College of Gastroenterology, and the New Mexico Medical Society.

 

Charles S. Hertz, M.D.

Specialty: Gastroenterology and Internal Medicine 
Dr. Charles Hertz attended the University of Pennsylvania School of Medicine for his medical degree. He completed a Residency in Internal Medicine at the University of Virginia in Charlottesville and a Fellowship in Gastroenterology at the Medical College of Virginia in Richmond. He is Board Certified in both specialties. He is a member of the American College of Gastroenterology and the New Mexico Medical Society.

 


Marianne Gibbs, RD, LD, CDE


Registered Dietitian Nutritionist/Certified Diabetes Educator
Registered Dietician, Certified Diabetes Educator, Marianne draws upon more than 25 years of experience to offer customized nutrition services as a member of our HealthCare Team and NNMGA. With the expertise, training and credentials that are vital for promoting positive lifestyle choices, Marianne's background includes: Diabetes, Cardiovascular Disease, Kidney Disease, Gastrointestinal Disorders, Weight Management and Disease Prevention.