U.S. Department of Health and Human Services

Digestive Diseases Branch Clinical Gastroenterology Fellows

Welcome to the Gastroenterology Fellowship Program at the National Institutes of Health!

The Digestive Diseases Branch at the National Institute of Diabetes, Digestive and Kidney Diseases has a long tradition of training fellows for a career in academic Gastroenterology and Hepatology. Under the leadership of Dr. Stephen Wank, Chief of the Digestive Diseases Branch, the program has a strong commitment to provide excellent training to its fellows to develop the skills necessary to become independent physician-scientists in the field of Gastroenterology and Hepatology.

The 3-year combined fellowship in Gastroenterology and Hepatology is a joint program with the University of Maryland Medical Center. The first year of the fellowship is purely clinical and is centered at the University of Maryland Medical Center and Baltimore VA Medical Center (BVAMC). The second and third years are spent at the NIH Clinical Center and predominantly focused on clinical and/or translational research.

Current Digestive Disease Branch Clinical Gastroenterology Fellows:​

Jim Chou, M.D.Jim Chou, M.D.

3rd year

Residency: Cedars-Sinai Medical Center / UCLA, Los Angeles, CA
Medical Degree: Boston University School of Medicine, Boston, MA

One of my gastrointestinal research projects focuses on study of Multiple Endocrine Neoplasia type-1, Zollinger-Ellison Syndrome and their genetic and phenotypic manifestations and correlations. Other areas of interest include roles of gut microbiome in gastrointestinal diseases and intestinal infections.

Nancy Ho, M.D.Nancy Ho, M.D.

3rd year

Residency: McGaw Medical Center of Northwestern University, Chicago, IL
Medical Degree: Feinberg School of Medicine, Northwestern University, Chicago, IL

I am currently involved in a study following the largest cohort of patients with chronic granulomatous disease, and I am helping to manage the gastrointestinal manifestations and complications of this rare disease. I am also involved in a phase 1 trial of sirolimus in the treatment of eosinophilic gastrointestinal disease. Finally, I am helping to characterize the gastrointestinal manifestations of a yet, unnamed familial mast cell degranulation disorder.

David Chascsa2.jpgDavid M. H. Chascsa, M.D.

2nd year
Residency: University of Colorado Denver, CO
Medical Degree: Georgetown University School of Medicine, Washington, DC
I have varied research projects covering a spectrum of gastroenterology and hepatology. These projects include: utilization of SmartPill© in the management of patients with gastroesophageal reflux disease; evaluation of the natural history of gastrointestinal and hepatic manifestations of patients with autoimmune polyendocrinopathy ectodermal dystrophy and candidiasis (APECED); and the use of noninvasive means to assess portal hypertension.

Derrick Tang2.jpgDerek Tang, M.D.

2nd year
Residency: Temple University Hospital, Philadelphia, PA
Medical Degree: Tulane University School of Medicine, New Orleans, LA
I am currently involved in two major research projects. The first involves evaluating the presentation, natural history, and diagnosis of familial midgut carcinoid tumor -- an entity that is distinct from sporadic carcinoid tumors. The second encompasses elucidating the association of Helicobacter pylori infection with metabolic syndrome and non-alcoholic fatty liver disease. My other areas of interest are colonoscopy screening and endoscopic safety.

Recent graduates and current position:

Mark T. Voellinger, M.D.Mark T. Voellinger, M.D.

Practicing Gastroenterologist, Ohio Valley Medical Center, Wheeling, WV

Thomas Simcox, M.D.Thomas Simcox, M.D.

Practicing Gastroenterologist, Anne Arundel, MD

Preet Bagi, M.D.Preet Bagi, M.D.

Inflammatory Bowel Disease Advanced Fellowship - University of California
San Diego Inflammatory Bowel Disease Center

Christopher Koh, M.D. M.H.Sc.Christopher Koh, M.D. M.H.Sc.

Staff Clinician, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases
National Institutes of Health

Sajneet Khangura, M.D.Sajneet Khangura, M.D.

Assistant Professor – Clinical Department of Medicine
Division of Digestive Diseases, The University of Mississippi Medical Center, Jackson, MS

Apurva Trivedi, M.D.Apurva Trivedi, M.D.

Assistant Professor – Texas A&M Health Science Center College of Medicine
Department of Gastroenterology, Scott & White Healthcare, Killeen, TX

Manish Arora, M.B.B.S.Manish Arora, M.B.B.S.

Practicing Gastroenterologist, Decatur, AL

Douglas Weinstein, M.D.Douglas Weinstein, M.D.

Staff Physician, Philadelphia VA Medical Center, Philadelphia, PA

Apurva Modi, M.D.Apurva Modi, M.D.

Transplant Hepatologist, Baylor All Saints Medical Center, Fort Worth, TX

Grishma Joy, M.D.Grishma Joy, M.D.

Chief, Inflammatory Bowel Disease Program, Washington Hospital Center

Erik von Rosenvinge, M.D.Erik von Rosenvinge, M.D.

Chief, Gastroenterology Section, VA Maryland Health Care System, Department of Veterans Affairs
Assistant Professor of Medicine, University of Maryland School of Medicine

Lakshmi Gopal, M.D.Lakshmi Gopal, M.D.

Practicing Gastroenterologist, Pensacola, FL

Michael Yao, M.D.Michael D Yao, M.D.

Director, Inflammatory Bowel Disease Program, Gastroenterology and Hepatology Section, Division of Medicine, Washington DC VA Medical Center
Assistant Professor, Division of Gastroenterology, Department of Medicine, Georgetown University Medical Center

Alireza Tabesh, M.D.Alireza Tabesh, M.D.

Practicing Gastroenterologist, Los Angeles, CA