People

Dr. Rehan Rais is an Instructor in Medicine at the Division of Hospital Medicine since June 2024. Originally from Karachi, Pakistan, he completed his medical education at Liaquat National Medical College. Dr. Rais completed his residency in anatomic and clinical pathology at Barnes-Jewish Hospital/Washington University School of Medicine, where he also served as a chief resident and participated in recruiting new residents. He further specialized in hepatobiliary and gastrointestinal pathology and is now a board-certified anatomic and clinical pathologist. Driven by his clinical interests, he pursued additional training in Internal Medicine, completing his internship and residency at Barnes-Jewish Hospital/Washington University School of Medicine. He is actively involved in quality improvement projects focusing on heart failure and improving primary care-patient continuity.

Samuel Reuter, PA-C, CAQ-HM, MMS is a Physician Assistant within the Division of Hospital Medicine at Washington University.  He received his Physician Assistant, Master of Medical Science degree from St. Louis University in 2021.  Upon graduating, Samuel completed a fellowship in hospital medicine from the University of Missouri and obtained a Certificate of Added Qualification in Hospital Medicine.  He is passionate about patient care, as well as furthering training and teaching opportunities for physician assistants.

Corey Shy, MD, is an Assistant Professor of Medicine at Washington University School of Medicine, committed to patient-centered care, education, and promoting diversity and inclusion within the medical community. Since joining the Division of Hospital Medicine in 2020, he has provided exceptional care to patients with complex medical needs, emphasizing interdisciplinary collaboration to optimize patient outcomes and reduce readmission rates. Dr. Shy is passionate about mentoring residents and medical students, especially in addiction medicine, aiming to bridge educational gaps and equip future physicians with necessary skills. His community service includes advocating for underrepresented minorities in medicine, reactivating the SNMA chapter at Texas A&M, and enhancing minority representation in residency programs. Dr. Shy's research focuses on improving patient care through innovative approaches, with significant contributions to colorectal cancer screening and addiction medicine.

Dr. Victoria Soncasie joined the Department of Medicine in Hospital Medicine as an Instructor with a secondary appointment in the Department of Pediatrics in the Division of Hospital Medicine in July 2026. She grew up in St. Louis prior to attending Truman State University in Kirksville, MO, where she graduated summa cum laude with Bachelors of Science in Biology and Spanish. Returning to her hometown, she attended medical school at Saint Louis University School of Medicine. Outside of her studies and clinical work, she dedicated her time to working on the operations of the school of medicine’s student-run free health clinic to provide healthcare to medically underserved people in the St. Louis area. Dr. Soncasie completed her internship and residency in Internal Medicine and Pediatrics at Indiana University School of Medicine. She is dedicated to excellence, clinical reasoning, and delivering high value care to her patients.

Kevin Stephenson, MD, is an Assistant Professor of Medicine in the Division of Hospital Medicine. Dr. Stephenson has two career foci: attending on inpatient general medicine teaching services at Barnes-Jewish Hospital and improving the treatment of undernourished children and pregnant women in sub-Saharan Africa. Alongside Mark Manary, Professor of Pediatrics at WUSM, Dr. Stephenson leads a research group that operates clinical trial networks in Sierra Leone, Malawi, and Ghana, across which novel formulations of therapeutic, supplementary, and school foods are tested in the hopes of treating undernutrition and improving physical and cognitive development in vulnerable populations. He had the good fortune of living in Malawi and Sierra Leone for several years; these experiences form the basis of his research career. Most recently, a trial published by Dr. Stephenson’s group was integral in changing the United Nations Codex Alimentarius regulations for the fatty acid content of ready-to-use therapeutic food, after showing that improved fatty acid balance led to superior cognitive development in children with severe acute malnutrition.

Jaclyn Stutz, FNP-BC, is a Nurse Practitioner within the Division of Hospital Medicine. She received her BSN at Bradley University in Peoria, Illinois. She started her nursing career in acute care medicine at BJH in 2011. She went on to receive her MSN at Maryville University. She joined the Division of Hospital Medicine as an NP in 2019. She serves on the Division’s Leadership Team.

Dr. David Tabagari joined the Division of Hospital Medicine as an Instructor in Medicine in July 2024. He was born and raised in Tbilisi, Republic of Georgia, and moved to the United States in 2021 to complete his Internal Medicine residency training. He attended and received his medical degree in 2017 from Tbilisi State Medical University. After graduating, he worked at “Multiprofile Clinic Consilium Medulla” in Tbilisi, Republic of Georgia, as a junior doctor and later as a resident physician in the hematology-oncology program, where he participated in various projects and was working on several major clinical trials. He is currently a co-founder of “Multiprofile Clinic Consilium Medulla” and is using his training and experience to be actively involved in implementing international standards to provide the highest quality medical care for patients in his home country. Dr. Tabagari completed his internship and residency at the University of Missouri School of Medicine in Columbia prior to joining the division in 2024. His current areas of interest are general internal medicine with a focus on inpatient care, with a special interest in hematology and oncology, as well as the detection and management of immunotherapeutic adverse events requiring hospitalization.

Jia Tang, MD joined the Department of Medicine in the Division of Hospital Medicine as an Instructor in July 2025. She grew up in the beautiful countryside of central China before attending Tongji Medical College, where she graduated with a medical degree and also completed the Internal Medicine residency program. After completing her residency training, Tang spent several years serving factory workers with work-related lung diseases in the rural areas of Shenzhen. While practicing medicine, Tang continued to nurture her passion for further medical education in the U.S. She began her journey with the USMLE and was accepted into the Internal Medicine residency program at St. Luke’s Hospital in Missouri. Along with her ongoing community service, she worked on a quality improvement project promoting the use of GLP-1 agonists and SGLT-2 inhibitors in diabetic patients and cultivated a love of teaching by tutoring medical students. Tang completed her Internal Medicine internship and residency at St. Luke’s Hospital in St. Louis from 2022 to 2025.

Shaili Tapiavala, MD joined the Division of Hospital Medicine in the Department of Internal Medicine as an Instructor in July of 2025. She was born in New York and soon moved to Dallas, Texas. She attended the University of Miami with merit scholarship and graduated with a bachelor’s degree in biology and public health and a minor in chemistry. She subsequently received her medical degree from Texas A&M College of Medicine in 2022. Tapiavala completed her internship and residency at Barnes-Jewish Hospital/WashU School of Medicine in St. Louis prior to joining the division in 2025. In addition to her clinical skills and research work, Tapiavala developed a strong interest in medical education and further enhanced her leadership abilities by completed the Forum for Women in Medicine Leadership Development Program. Her current areas of interest focus on health equity in oncologic care and treatment-related toxicity and its implications for patient morbidity.

Mark Thoelke, MD, is a Professor of Medicine and a Senior Fellow of Hospital Medicine. Mark was the first hospitalist at Barnes-Jewish Hospital in 1998. He helped found the division in 2000 and was Clinical Director, and then Chief until 2020. He now enjoys spending time on the teaching service.

Alex Thomas, MD, is an Assistant Professor of Medicine within the Division of Hospital Medicine. Specializing as a nocturnist, he tends to the diverse needs of patients across various service lines at Barnes-Jewish and Barnes-Jewish West County Hospitals. His dedicated focus extends to oncology, bone-marrow transplant, and general hospitalist services. Beyond his clinical pursuits, he is deeply committed to medical education, sharing his expertise on the Medicine Firm services. His passion for advancing healthcare extends to the realm of electronic health records, where he actively collaborates with fellow hospitalists across the BJC system to develop AgileMD pathways, setting a standard for patient care. He also serves on multiple committees and has played a pivotal role in the creation of the Roads to Success program, providing support to junior faculty members.

Evelyne Thomas, AGACNP-BC, is a Nurse Practitioner with a background in general medicine, acute care, and infectious disease. She has an interest in languages, and in immigrant and community health. She previously volunteered with Casa de Salud in St. Louis, and with the Pulmonary Brigade in Catacamas, Honduras with the International Medical Assistance Foundation. She has bachelor's degrees in English, Spanish, and nursing, and speaks conversational Spanish. She has worked in nursing since 2007, in general medicine and in the ICU, and graduated in 2014 with a master’s degree as an Adult and Gerontology Acute Care nurse practitioner from Goldfarb School of Nursing at Barnes-Jewish Hospital. She previously worked as an NP with infectious disease and joined the Division of Hospital Medicine at Washington University as an NP in 2015. She is committed to providing excellent individualized care to every patient.

Mathew Thomas, MD, joined the Division of Hospital Medicine as an Instructor in Medicine in July 2025. He was born in Buffalo, NY and spent most of his upbringing in Eau Claire, WI. He graduated from Boston College, MA, with a major in Mathematics and a minor in Chemistry. Thereafter, he went to medical school at Kasturba Medical College, India. He developed a particular interest in hematology/oncology and was involved in the Hemophilia Society of Manipal, educating and treating patients with recombinant clotting factor infusions for patients with hemophilia. During his residency in Internal Medicine at Riverside Medical Center in Kankakee, IL, he co-authored a quality improvement project detailing the unnecessary use of antibiotics in the treatment of asymptomatic bacteriuria. His clinical interests include preventative medicine, hematology/oncology, inpatient care, and delivering high quality patient care in underserved areas.

Lauren Van Buren, MD, is an Instructor in Medicine in the Division of Hospital Medicine. She received her medical degree from Indiana University School of Medicine and completed her internal medicine residency at Washington University in St. Louis. Her areas of interest include inpatient medicine, gastroenterology, physician wellness, and medical education. She is a member of the Social and Wellness committee within the division. She works as an attending physician primarily on the general medicine and oncology hospitalist services. 

Aarthi Venkatramanan, MD joined the Division of Hospital Medicine in the Department of Internal Medicine as an Instructor in July 2025. Her diverse upbringing—spending her early years in the United States and later completing her education in India—has shaped a global perspective that enhances both her clinical approach and patient care. Venkatramanan graduated with Honors from Kasturba Medical College in Manipal, India, in 2021. Following medical school, she worked as a medical scribe in Texas, gaining valuable experience in outpatient rheumatology before beginning her Internal Medicine residency at Georgetown University/Hospital Center in Washington, DC. She is passionate about mentoring medical trainees and aspires to integrate medical education into her long-term career. Her clinical interests include General Internal Medicine, Pulmonary and Critical Care Medicine, and Transplant Medicine, with plans to pursue subspecialty training in the future.

Mallorie Vest, MD, joined the Division of Hospital Medicine in the Department of Internal Medicine as an assistant professor in December 2023. She received her bachelor's degree in Molecular and Cellular Biology with a minor in Chemistry from the University of Illinois at Urbana-Champaign. In 2020, she completed her medical degree at St. George's University School of Medicine in Grenada, followed by clinical rotations in Miami, Florida, and New York City. Dr. Vest further pursued her medical career by completing her internship and residency in Internal Medicine at Icahn School of Medicine, New York City Health and Hospitals, Queens. Dr. Vest is also certified in various hospitalist procedures. Throughout her professional journey, Dr. Vest has demonstrated a range of interests. She has authored papers on internal medicine topics such as pancreatitis, neuroendocrine carcinoma, and breast cancer.

Nikita Wadhwani, MD, joined the Department of Medicine in the Division of Hospital Medicine as an Instructor in July 2025. Wadhwani received her medical degree in 2018 from the University of Delhi and recently completed her Internal Medicine residency training at Hackensack Meridian Health in NJ. She actively partook in the development and implementation of resident mentorship initiatives and worked closely with other co-mentors to strategically devise tailored plans aimed at easing the transition, and progression of mentees through various clinical competency milestones. She worked toward eliminating impediments to healthcare access and facilitating provision of resources to the medically underserved cohorts through her continual participation in community outreach events, health education initiatives, health & wellness fairs, and curbside/drive-through vaccination programs. Wadhwani is greatly passionate about diversity, equity, and inclusion, and graduate medical education, and she looks forward to teaching and working with medical students and residents.

Devvrat Yadav, MD joined the Division of Hospital Medicine in the Department of Internal Medicine as an Instructor in July 2025. He completed his medical school from the All India Institute of Medical Sciences (AIIMS), New Delhi, the most prestigious medical institute in India. Following medical school, Yadav completed a two-year Postdoctoral Research Fellowship in the Division of Gastroenterology and Hepatology at Mayo Clinic School of Medicine in Rochester, Minnesota. He went on to complete his Internal Medicine residency at Sinai Hospital of Baltimore, Maryland. During residency, he continued to explore the role of the gut microbiome, with a particular focus on gastrointestinal cancers and CAR T-cell therapy. Yadav’s academic passions include medical education, clinical research, and mentoring. He is particularly interested in bedside physical examination, high-value care, and delivering efficient, patient-centered treatment in the inpatient setting.

Robert Young, MD, MS, is a dedicated geriatrics hospitalist at Washington University School of Medicine, specializing in providing excellent inpatient care for vulnerable elderly patients. His clinical activities include attending to patients on hospitalist floors, performing geriatrics consults, and collaborating with interdisciplinary teams to improve care outcomes. Dr. Young has a particular focus on delirium care models, post-acute care transitions, and interdisciplinary teamwork to maintain patient functionality. He has contributed to quality improvement and patient safety by implementing diagnostic excellence programs and developing protocols to enhance patient mobility and reduce falls. In education, Dr. Young mentors medical learners, teaches on geriatrics consult service, and develops simulation-based training programs. Dr. Young is also actively involved in service and citizenship, participating in various committees and task forces to advocate for better patient care and support for underrepresented groups.

Beth Younger, APRN-CNP, is an Acute Care Nurse Practitioner within the Division of Hospital Medicine. She received her Bachelor of Science in Nursing from Goldfarb School of Nursing in 2012. She went on to receive her Doctor of Nursing from Saint Louis University in 2021. She has experience working in the Neuro ICU and Post Anesthesia Care Unit. She joined the Division of Hospital Medicine in 2024.

Dr. Yu joined the Division of Hospital Medicine at Washington as an Instructor in Medicine in July 2024. She grew up in Iowa City, Iowa, and completed both undergraduate studies, medical education, and residency training in the Midwest. She attended college at Washington University in St. Louis and graduated cum laude in 2017 with a Bachelor of Science in Engineering in Biomedical Engineering. After college, she attended medical school at the University of Iowa Carver College of Medicine and received her medical degree in 2021. She was inducted into the Carver Humanism Honor Society in 2020. She then completed her residency training in Internal Medicine at the University of Iowa Hospitals and Clinics from 2021 to 2024. Her wide range of exposure and her various experiences during residency training pushed her interest toward hospital medicine, and she decided to pursue a career as an academic hospitalist.

Brenna Zack, NP, is an Adult-Gerontology Acute Care nurse practitioner within the Division of Hospital Medicine. She received her BSN from Southeast Missouri State University in 2015. Her nursing experience includes time in acute care medicine and emergency medicine. She went on to receive her MSN from Maryville University in 2019 and joined the Division of Hospital Medicine in March 2020. She is committed to providing excellent patient care and furthering education for both nurse practitioner students and APCs within the division.

Dr. Samuel Zetumer joined the Division of Hospital Medicine in the Department of Internal Medicine as a current Assistant Professor of Medicine in October 2025. He was born and raised in San Diego, California, and graduated cum laude from Princeton University with a degree in Mathematics. He then attended the University of California, San Francisco, where he obtained a medical degree and a master’s in clinical research and study design. Afterwards, he attended the University of Iowa for his internal medicine residency. Dr. Zetumer specializes in the creation and deployment of software to facilitate clinical research, enhance and monitor care quality, improve operational efficiency, and augment patient care directly. As the CHIO, Dr. Zetumer worked across multidisciplinary teams to upgrade clinical data servers safely, overhaul inpatient electronic medical record (EMR) functionality, translate primary research into dashboards for specialists to use during consultation, and migrated on-premise platforms to the VA’s Azure environment.

David Zhang, MD joined the Division of Hospital Medicine in the Department of Internal Medicine as an Instructor in June 2025. He was raised in San Antonio, Texas. He attended Washington University in St. Louis, where he studied physics and graduated with college honors. During his time in college, was inducted into the physics honor society, Sigma Pi Sigma, and did research in biophysics and epigenetics. Zhang then completed his internship and residency at Barnes-Jewish Hospital / WashU School of Medicine prior to joining the division in 2025. During his time in residence, he has maintained an interest in medical education. His current interests are general internal medicine with a special interest in pulmonology and critical care. He is also eager to mentor trainees and students, and to further his interest in medical education.

Dr. Jiahua Zhang joined the Division of Hospital Medicine as an Instructor in Medicine in July 2024. He was born and raised in Changsha, China, and came to the United States in 2011 for college. He attended the University of Washington in Seattle and graduated with a bachelor’s degree in biochemistry in 2015. After graduation, he worked as a lab technician, serving patients in need of diagnostic tests for 2 years. He started his medical training at Touro College of Osteopathic Medicine in Middletown, New York, in 2017 and received his medical degree in 2021. Dr. Zhang completed his residency in internal medicine at the Mercy Hospital in St. Louis in 2024 and joined the division in the same year. He was enthusiastic about developing clinical skills in using point-of-care ultrasound (POCUS) during his practice and received the certificate to perform a full-body POCUS exam during the third year of his residency. His clinical interests include general internal medicine with a focus on inpatient care, hematology and oncology, and the clinical education of medical students and residents.

Diana Zhao, MD, PhD is an Assistant Professor of Medicine in the Division of Hospital Medicine and works primarily as a night hospitalist. She has an interest in teaching and mentorship of students on the hospitalist service and aids in recruitment of internal medicine resident candidates through the IM program as an interviewer. She also serves on the Patient Care Operations Committee.