Link to: ROBERT J. PONEC, MD
Robert J. Ponec, M.D., F.A.C.P., F.A.C.G., F.A.S.G.E., A.G.A.F
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroLink to: Makkalearn Em, M.D.
Makkalearn Em, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroLink to: Katherine Hoda, M.D.
Katherine Hoda, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroLink to: Nabil Choueiri, M.D.
Nabil Choueiri, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroLink to: Falguny Bhavan, M.D.
Falguny Bhavan, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroLink to: Nizar Senussi, M.D.
Nizar Senussi, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroLink to: Sandi Fields, M.D.
Sandi Fields, M.D.
Board Certified Gastroenterology
Salem GastroLink to: Shyam Dang, M.D.
Shyam Dang, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology and Hepatology
Salem GastroLink to: Charles Du, M.D.
Charles Du, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroLink to: Eric Tatro, M.D.
Eric Tatro, M.D.
Board Certified Internal Medicine, Board Certified Gastroenterology
Salem GastroPhysician Assistants
Chandler Boyd, PA-C
National Certification as a Physician Assistant
Salem GastroBIO
Chandler Boyd, PA-C joins us from Illinois. He attended Southern Illinois University for his Master of Science in Physician Assistant Studies. He earned a Bachelor of Science degree in Exercise Science at Utah Valley University, College of Science and Health. Chandler has worked in the medical field since 2017 in various roles.
Daniel C. Butler, PA-C, M.S., M.P.A.S.
National Certification as a Physician Assistant
Salem GastroBIO
Daniel C. Butler PA-C is a graduate of University of Iowa College of Medicine Physician Assistant Program, where he completed both his physician assistant certification and a Master of Physician Assistant Studies degree. Prior to admission to the Physician Assistant program, Mr. Butler received a Master of Science degree from Colorado State University in Human Anatomy and Physiology. Mr. Butler had seven years’ experience in primary care medicine prior to joining SGC.
Amy Ditzel, PA-C
National Certification as a Physician Assistant
Salem GastroBIO
Amy Ditzel, PA-C, is a board-certified physician assistant specializing in gastroenterology. She brings more than 20 years of clinical experience and a warm, patient-centered approach to digestive care. Amy is passionate about helping patients feel comfortable discussing their symptoms and confident in managing their health. She earned her Master of Science in Physician Assistant Studies from Seton Hall University and her Bachelor of Science in Biology from Pennsylvania State University. Before joining Salem Gastroenterology in 2017, Amy practiced in primary care for 15 years. Originally from New Jersey, she enjoys exploring Oregon with her husband, three children, and their dog.
Michael Slabaugh, PA-C
National Certification as a Physician Assistant
Salem GastroBIO
Michael Slabaugh, PA-C, is a board-certified physician assistant specializing in gastroenterology. He brings over a decade of experience in digestive health and a calm, patient-centered approach to care. Michael earned his Master of Physician Assistant Studies from Rosalind Franklin University of Medicine and Science and his Bachelor of Arts in Art History from Indiana University. Before joining Salem Gastroenterology in 2015, he practiced at Mid-Valley Gastroenterology in Corvallis. Outside of the clinic, Michael enjoys spending time with his wife and children, biking, hiking, skiing, traveling, and exploring art and architecture.
Thomas Nasr, PA-C
National Certification as a Physician Assistant
Salem GastroBIO
Thomas Nasr, PA-C, is a board-certified physician assistant specializing in gastroenterology and internal medicine. He brings a patient-centered, education-focused approach to digestive health and is a valued member of the Salem Gastro care team. Thomas is passionate about helping patients regain control over their GI health. He emphasizes listening closely to patient concerns and ensuring they feel heard. His care philosophy is rooted in education—he believes patients make the best health decisions when they fully understand their condition and treatment options. Thomas earned his Master of Physician Assistant Practice from Ohio University and holds a Bachelor of Science in Microbiology from the University of California, Davis. He also completed a hospital internal medicine fellowship at the Mayo Clinic, where he rotated through hepatology, neurology, hematology, palliative care, critical care, and more. Outside of the clinic, Thomas enjoys playing and writing music, spending time with his wife and their dog, and exploring the outdoors.
Adnan Ahmad, PA-C
National Certification as a Physician Assistant
Salem GastroBIO
Adnan Ahmad, PA-C, is a board-certified physician assistant at Salem Gastro who brings a goal-driven, patient-centered approach to digestive health. He believes that the most effective care comes from understanding what matters most to the patient—and working together to achieve it. Adnan earned his Master of Science in Physician Assistant Studies from Albany Medical College and holds a Bachelor of Arts in Psychology with a minor in Biology from SUNY Geneseo. His clinical training included rotations in internal medicine, emergency care, cardiothoracic surgery, GI surgery, psychiatry, and pediatrics. Prior to joining Salem Gastro, he gained experience as a medical assistant, patient care technician, and supplemental instructor in human biology. Born in a small village in Pakistan and raised in upstate New York, Adnan is a first-generation college graduate and a passionate advocate for patient empowerment. He moved to Oregon to pursue both professional growth and outdoor adventure. Outside of work, Adnan enjoys trail running, marathons, cycling (road, mountain, and gravel), skiing, and exploring the Pacific Northwest’s natural beauty.