U.S. Department of Health and Human Services

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


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

Residency: Cedars-Sinai Medical Center / UCLA, Los Angeles, CA
Medical Degree: Boston University School of Medicine, Boston, MA
Year in Program: 3rd year
Research Projects: 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.

Residency: McGaw Medical Center of Northwestern University, Chicago, IL
Medical Degree: Feinberg School of Medicine, Northwestern University, Chicago, IL
Year in Program: 3rd year
Research Projects: 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.

Residency: University of Colorado Denver, CO
Medical Degree: Georgetown University School of Medicine, Washington, DC
Year in Program: 2nd year
Research Projects: 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.

    Residency: Temple University Hospital, Philadelphia, PA
    Medical Degree: Tulane University School of Medicine, New Orleans, LA
    Year in Program: 2nd year
    Research Projects: 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 Fellows 


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

    Current Position: Practicing Gastroenterologist, Ohio Valley Medical Center, Wheeling, WV


    Thomas Simcox, M.D.

    Thomas Simcox, M.D.

    Current Position: Practicing Gastroenterologist, Anne Arundel, MD


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

    Current Position: 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.

    Current Position: 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.

    Current Position: 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.

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


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

    Current Position: Practicing Gastroenterologist, Decatur, AL

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

    Current Position: Staff Physician, Philadelphia VA Medical Center, Philadelphia, PA

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

    Current Position: Transplant Hepatologist, Baylor All Saints Medical Center, Fort Worth, TX


    Grishma Joy, M.D.

    Current Position: Chief, Inflammatory Bowel Disease Program, Washington Hospital Center                             



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

    Current Positions: 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.   

      Current Position: Practicing Gastroenterologist, Pensacola, FL



      MMichael D Yao M.D.ichael D Yao, M.D. 

      Current Positions: 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.

      Current Position: Practicing Gastroenterologist, Los Angeles, CA