Our Physicians

DR. David A. Tessler

D.O, FACG, FACOI
Gastroenterologist
(480) 834-0771

DR. David A. Tessler, D.O. , FACG, FACOI

A graduate of the University of Michigan and Midwestern University-Chicago College of Osteopathic Medicine, Dr. Tessler completed his residency at Bostford General Hospital in Michigan. He completed both a research fellowship in Gastrointestinal Oncology and a Fellowship in Gastroenterology at Henry Ford Hospital in Detroit, Michigan. He has been in practice since 2005 and is a member of the American Gastroenterological Association, American Osteopathic Association, American College of Gastroenterology, and the American College of Osteopathic Internists. He is a published author and is Board Certified. A native of West Bloomfield, Michigan, Dr. Tessler is married and has two children. He enjoys basketball and bicycle riding.

Dr. David B. LEFF

D.O.
Gastroenterologist
(480) 834-0771

Dr. David B. LEFF, D.O.

Dr. Leff graduated in 1991 from the Des Moines University, College of Osteopathic Medicine, Des Moines, Iowa. He completed his residency in Internal Medicine in 1995 and his Fellowship in Gastroenterology in 1997 at The Western Pennsylvania Hospital in Pittsburgh, Pennsylvania. Dr. Leff has been in practice in Arizona since coming here in 1997. He is on the Medical Advisory Board for the American Liver Foundation Southwest Chapter. He has a special interest in IBS and liver disease along with heartburn and colon cancer screening.

Dr. Carlos F. Zapata Antigoni

M.D.
Gastroenterologist
(480) 834-0771

DR. Carlos F. Zapata Antigoni, M.D.

Dr. Zapata obtained his medical degree at Universidad Peruana Cayetano Heredia in Lima, Peru where he is originally from. He completed his residency in Internal Medicine in Chicago, IL and his Fellowship in Gastroenterology at Banner Good Samaritan Medical Center (currently known as Banner University Medical Center Phoenix) in Phoenix, AZ. Areas of interest include Gastro-Esophageal Reflux Disease, Colon Cancer Screening and Biliary Disorders including procedures like ERCP. Dr. Zapata is a member of the American College of Gastroenterology, American Gastroenterology Association, American Society for Gastrointestinal Endoscopy and Phoenix GI Society. He is board certified in Internal Medicine and Gastroenterology. Dr. Zapata is bilingual, fluent in English and Spanish. He is married with two children with whom he shares his passion for basketball.

Dr. Sara E. Ancello

D.O.
Gastroenterologist
(480) 834-0771

Dr. Sara E. Ancello, D.O.

Dr. Sara Ancello, D.O. is a Board Certified Gastroenterologist, who specializes in the diagnosis and management of diseases of the gastrointestinal tract and liver. She received her medical degree from Nova Southeastern University, College of Osteopathic Medicine in Florida. She completed her Internal Medicine Residency as Chief Resident at Rowan University in New Jersey. She then moved to Arizona to complete her Fellowship in Gastroenterology through Midwestern University at Mountain Vista Medical Center, where she led her colleagues as Chief Fellow for two years. During her fellowship, Dr. Ancello spent three months focused on Transplant Hepatology at the Mayo Clinic in Scottsdale and Banner University in Phoenix. In 2020 Dr. Ancello was honored with the “Teaching Attending of the Year” Award by the Gastroenterology Fellowship.
Dr. Ancello has a special interest in the treatment of liver disease, inflammatory bowel disease and colorectal cancer prevention. She is an active member of the American College of Gastroenterology (ACG), American Gastroenterological Association (AGA), American Association for the Study of Liver Diseases (AASLD), the American Society for Gastrointestinal Endoscopy (ASGE), Crohn’s and Colitis Foundation (CCF), American College of Osteopathic Internists (ACOI) and the American Osteopathic Association (AOA). Dr. Ancello has numerous journal publications and poster presentations. She has lectured locally, nationally and internationally on Gastrointestinal Diseases, Emotional Intelligence and Leadership Development.
When it comes to your health, Dr. Ancello believes in providing the most up to date, evidence-based, quality and compassionate care. She strives to create long-lasting patient relationships using shared decision making to guide treatment plans. Dr. Ancello is proficient in conversational and medical Spanish. She prides herself in treating her patients as she would members of her own family.
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