Current & Recent Gastroenterology Fellows

Learn more about current and recent University of Maryland/NIH Clinical Scholars Gastroenterology Fellowship Program fellows below. You can also view a list of recent Gastroenterology Fellow Publications to learn more about research project findings.

Current Fellows

Carolina Versaille, M.D.
Carolina Versaille, M.D.

Residency: Mount Sinai Beth Israel

Medical School: St. George’s University School of Medicine Grenada

Year in Program: 3rd Year

Research Projects: My research centers on eosinophilic gastrointestinal diseases (EGIDs), with a particular emphasis on eosinophilic esophagitis (EoE) as well as other non-EoE EGIDs. Currently, I am investigating the impact of multi-segment eosinophilia on both disease management and clinical outcomes in EoE. Through this work, I aim to shed light on how these patterns of inflammation affect patient care.

A second area of interest is the prevalence of Barrett’s esophagus and esophageal cancer in individuals with Fanconi anemia (FA). FA is a rare, multisystem inherited disorder characterized by bone marrow failure and an increased risk of malignancy, including squamous cell carcinoma (SCC). Approximately 7% of patients with FA are born with congenital gastrointestinal tract anomalies. However, even in the absence of congenital malformations, individuals with FA appear to be at increased risk for gastroesophageal reflux disease (GERD), Barrett’s esophagus, and esophageal squamous cell carcinoma. My goal is to better define this risk in order to inform screening, surveillance, and clinical management.

Asif Hitawala, M.B.B.S.
Asif Hitawala, M.B.B.S.

Residency: Cleveland Clinic Foundation/Fairview Hospital

Medical School: Ravindra Nath Tagore Medical College

Year in Program: 3rd Year

Research Projects: I have broad research interests in Gastroenterology and Hepatology. My focus has been eosinophilic gastrointestinal diseases (EGID) as well as viral hepatitis and liver involvement in other diseases such as systemic lupus erythematosus. I am currently working with a team at National Institute of Allergy and Infectious Diseases to identify outcomes and treatment strategies in patients with various EGID using the CEGIR consortium data. During my Hepatology fellowship at NIH, I worked on identifying factors that predict Hepatitis B functional cure and continue to work on identifying novel markers of the same. I also have interest in rare liver diseases such as Fontan associated liver disease.

Gina Moon, M.D.
Gina Moon, M.D.

Residency: University of Oklahoma Health Services Center

Medical School: University of Oklahoma College of Medicine

Year in Program: 2nd Year

Kareen Akiva, M.D.
Kareen Akiva, M.D.

Residency: University of Maryland Medical Center

Medical School: Ben-Gurion University of the Negev Faculty of Health Sciences Israel

Year in Program: 2nd Year

Alumni Testimonials

My fellowship at the NIH was truly extraordinary. With outstanding mentorship from dedicated faculty, I gained invaluable expertise navigating rare and complex conditions. The program’s robust research opportunities ignited my curiosity and honed my skills, ensuring I stepped into practice with confidence and precision. I’m forever grateful for an experience that so thoroughly prepared me for a fulfilling career in gastroenterology.

~Bryan Curtin, M.D, M.H.Sc.

Post Fellowship Training: NIH-Duke Master’s Program in Clinical Research Neurogastroenterology and Motility Advanced Fellowship – Augusta University Digestive Health Center, Augusta, GA
Current Position: Director, The Center for Neurogastroenterology and GI Motility, Mercy Medical Center

A fellowship at the NIH is very unique in that it balances a strong focus on clinical and endoscopic skills with a vast array of research opportunities. As a fellow, I had the opportunity to manage patients with various rare pathologies and to collaborate closely with other clinical specialties. Moreover, I was able to get involved with a number of research projects early on, which led to poster presentations and publications. However, the best part of being at the NIH, were the people. I was surrounded by a great group of co-fellows, as well as brilliant and supportive attendings, who made my training not just successful, but also incredibly enjoyable and fun.

~Anna Strongin, M.D.

Current Position: Practicing Gastroenterologist, Capital Digestive Care, MD

Fellowship through the UMMS/NIH Clinical scholars program set me up for success as an academic transplant hepatologist. The combination of robust clinical exposure both in large academic hospitals and the unique clinical training environment of NIH offered a well-rounded experience to gain expertise in the clinical management of common gastrointestinal and hepatic disorders, and the scientific evaluation of complex and rare diseases. Mentors at NIH helped solidify the fundamentals of clinical research which furthered my interest in academic medicine positioning me well beyond fellowship. I am grateful to the faculty and for the training experience!

~David M. H. Chascsa, M.D.

Post Fellowship Training: Transplant Hepatology Advanced Fellowship - Mayo Clinic, Scottsdale, AZ
Current Position: Assistant Professor of Medicine; Program Director- Transplant Hepatology, Mayo Clinic, Scottsdale, AZ

Recent Fellows

Alla Turshudzhyan, D.O.

Current Position: Assistant Professor of Medicine, University of Maryland Medical Center

Xixi Xu, M.D.

Post Fellowship Training: Advanced Endoscopy Fellowship – University of Massachusetts

Gracia M. Viana Rodriguez, M.D.

Current Position: Acting Gastroenterologist – Northern Light Health

Disha Sharma, M.D.

Current Position: Acting Gastroenterologist - MedStar Health

Bilal Khalid, M.D.

Post Fellowship Training: Transplant Hepatology Fellowship – Mayo Clinic

Current Position: Assistant Professor of Medicine, Johns Hopkins University

Hanna Blaney, M.D., M.P.H.

Post Fellowship Training: Hepatology Transplant Fellowship – Georgetown University

Current Position: Assistant Professor of Medicine, Virginia Commonwealth University

Anusha Vittal, M.D.

Current Position: Acting Gastroenterologist - MedStar Health

Walter Lai, M.D., Ph.D.

Current Position: Acting Gastroenterologist - Meritus Health

Bilal Asif, M.D.

Post Fellowship Training: Hepatology Transplant Fellowship – Mayo Clinic

Current Position: Clinical Assistant Professor, NYU Grossman Long Island School of Medicine

Alex Yang, M.D.

Post Fellowship Training: Hepatology Transplant Fellowship - Massachusetts General Hospital

Current Position: Assistant Professor of Medicine, University of California, San Diego

Monica Passi, M.D.

Post Fellowship Training: Advanced Endoscopy Fellowship –North Shore University/Long Island Jewish Medical Center (Northwell Health)
Current Position: Acting Gastroenterologist, Gastro Center of Maryland

Sumona Bhattacharya, M.D.

Post Fellowship Training: Advanced Inflammatory Bowel Disease Fellowship – NYU Grossman School of Medicine
Current Position: Assistant Professor of Medicine, George Washington University Medical Faculty Associates

Ben Da, M.D.

Post Fellowship Training: Transplant Hepatology Advanced Fellowship – Icahn School of Medicine at Mount Sinai
Current Position: Senior Associate Director Clinical Development. Gilead Sciences, Inc

Natasha Kamal, M.D.

Post Fellowship Training: Inflammatory Bowel Disease Fellowship – University of Maryland

Current Position: Acting Gastroenterologist, Frederick Gastroenterology Associates

Bryan Curtin, M.D., M.H.Sc.

Post Fellowship Training: NIH-Duke Master’s Program in Clinical Research

Post Fellowship Training: Neurogastroenterology and Motility Advanced Fellowship – Augusta University Digestive Health Center, Augusta, GA

Current Position: Director, The Center for Neurogastroenterology and GI Motility, Mercy Medical Center

Ehsan Chitsaz, M.D., M.H.Sc.

Current Position: Acting Gastroenterologist, TriHealth

Sonia Taneja Sharma, M.D.

Current Position: Assistant Professor of Clinical Medicine, Keck School of Medicine of USC

Samuel Schueler, M.D.

Current Position: Assistant Professor of Medicine, George Washington University Medical Faculty Associates; Program Director - George Washington University GI Fellowship Program

Hawwa Alao, M.D.

Post Fellowship Training: Interventional Gastroenterology Fellowship - Harbor UCLA Medical Center
Current Position: Practicing Gastroenterologist, Swedish Health Services

Anna Strongin, M.D.

Current Position: Practicing Gastroenterologist, Capital Digestive Care, MD

David M. H. Chascsa, M.D.

Post Fellowship Training: Transplant Hepatology Advanced Fellowship - Mayo Clinic, Scottsdale, AZ
Current Position: Assistant Professor of Medicine, Program Director - Transplant Hepatology, Mayo Clinic (Scottsdale)

Derek M. Tang, M.D.

Current Position: Practicing Gastroenterologist, Kaiser Foundation Hospital - Orange County, Anaheim, CA

Nancy Ho, M.D

Current Position: Practicing Gastroenterologist, Sutter Health- California Pacific Medical Center, San Francisco, CA

Jim Y. Chou, M.D.

Current Position: Practicing Gastroenterologist, United Gastroenterologists, Orange County CA

Mark T. Voellinger, M.D.

Current Position: Practicing Gastroenterologist, Wheeling Hospital

Thomas Simcox, M.D.

Current Position: Practicing Gastroenterologist, Anne Arundel Gastroenterology

Preet Bagi, M.D.

Post Fellowship Training: Inflammatory Bowel Disease Advanced Fellowship - University of California, San Diego Inflammatory Bowel Disease Center

Current Position: Saddleback Medical Group, Laguna Hills, CA

Current Position: Clinical Director, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health

Sajneet Khangura, M.D.

Current Position: Practicing Gastroenterologist, Gastroenterology Consultants of San Antonio

Apurva Trivedi, M.D.

Current Position: Practicing Gastroenterologist, Texas Digestive Disease Consultants

Manish Arora, M.B.B.S.

Current Position: Practicing Gastroenterologist, Decatur, AL

Doug Weinstein, M.D.

Current Position: Director, Advanced Gastrointestinal (GI) Motility Program, CapitalHealth Medical Center- Pennington, NJ

Apurva Modi, M.D.

Post Fellowship Training: Transplant Hepatology Advanced Fellowship- University of Maryland
Current Position: Transplant Hepatologist, Baylor All Saints Medical Center, Fort Worth, TX

Erik von Rosenvinge, M.D.

Current Positions: Professor of Medicine, University of Maryland School of Medicine; Vice Chair, Department of Medicine; Director, Medical Care Clinical Center, VA Maryland Health Care System

Michael D. Yao, M.D.

Current Positions: Chief, Gastroenterology and Hepatology Section. Washington DC VA Medical Center. Associate Professor of Medicine, George Washington University.

Last Reviewed August 2026