Department of Medicine
Gastroenterology & Hepatology
Division Chief
Juanita Merchant, MD, PhD
Regents Professor
Professor, Medicine
Chief, Division of Gastroenterology & Hepatology
Research Member, Cancer Biology Program, University of Arizona Cancer Center
Associate Director for Basic Sciences, University of Arizona Cancer Center
Faculty
Avin Aggarwal, MBBS
Associate Program Director, GI Fellowship Program
Clinical Assistant Professor
Medical Director, South Campus Endoscopy Services
![[John Moses Azizian, MD]](/sites/default/files/styles/az_card_image/public/2026-03/Azizian_John-MD_GASTRO-25_0846-5-Edit.jpg.webp?h=15a84aa4&itok=vOMYiNvn)
John M. Azizian, MD
Fellow, Chief
Associate Clinical Instructor, Medicine
Rilwan Balogun, MD
Assistant Clinical Professor, Medicine - (Clinical Series Track)
Bhaskar Banerjee, MD
Professor Emeritus of Medicine
Professor of Optical Sciences and Biomedical Engineering
Program Director, Gastroenterology Fellowship
Geoffrey Block, MD, MSc, FACP
Clinical Professor of Medicine
Medical Director, Liver Transplant
Interim Director, Thomas D. Boyer Liver Institute
Shiv Bomman, MBBS
Fellow
Associate Clinical Instructor, Medicine
![[Shoma Bommena, MBBS]](/sites/default/files/styles/az_card_image/public/2026-03/Bommena_Shoma-MBBS_GI-whitecoat-1_24_0855.jpg.webp?h=8e518af9&itok=7Zw0f8Ma)
![[Malini Chauhan, MD]](/sites/default/files/styles/az_card_image/public/2026-03/Chauhan_Malini_25_0846-5-Edit_5x7.jpg.webp?h=a4ccbdbd&itok=D2c9Ju6K)
Malini Chauhan, MD
Fellow, Chief
Associate Clinical Instructor, Medicine
Susana Escalante-Glorsky, MD
Assistant Clinical Professor, Medicine - (Clinical Series Track)
Joshua Melson, MD
Program Director, Gastroenterology Fellowship
Clinical Professor of Medicine
Director, High-Risk Clinic for Gastrointestinal Cancers, University of Arizona Cancer Center
Juanita Merchant, MD, PhD
Regents Professor
Professor, Medicine
Chief, Division of Gastroenterology & Hepatology
Research Member, Cancer Biology Program, University of Arizona Cancer Center
Associate Director for Basic Sciences, University of Arizona Cancer Center
Bhupesh Pokhrel, MBBS
Assistant Clinical Professor, Medicine
Matthew Reif, MD
Fellow
Associate Clinical Instructor, Medicine
Karen M. Rico, MD
Fellow
Associate Clinical Instructor, Medicine
![[Jaime Scott, MD]](/sites/default/files/styles/az_card_image/public/2026-03/Scott_Jaime_25_0846-6-Edit-2.jpg.webp?h=8e8e1180&itok=z6YuBkWn)
Jaime Scott, MD
Fellow, Chief
Associate Clinical Instructor, Medicine
Sasha Taleban, MD
Associate Professor, Medicine - (Clinical Scholar Track)
Associate Program Director, Gastroenterology & Hepatology Fellowship
Director, Inflammatory Bowel Disease Program
![[Brandon Witten, MD]](/sites/default/files/styles/az_card_image/public/2026-03/Witten_Brandon_25_0846-7-Edit-1.jpg.webp?h=89ae1ea9&itok=NqQjt0fa)
Research Staff
Maria Gordon, MS
Director, Clinical Research Operations; Clinical and Translational Sciences (CATS) Research Center and Clinical and Translational Science Awards (CTSA) Program, College of Medicine – Tucson
