GI & Hepatology Physicians


Dr. Olga ArondiasOlga Aroniadis, MD, MSc, FACG

Svetlana Koroleva Endowed Professor in Gastroenterology
Division Chief, Gastroenterology & Hepatology
Associate Professor of Clinical Medicine
Director, Masters in Epidemiology and Clinical Research Program, Program of Public Health
Director, Women’s Health Center for Gastroenterological Diseases and Disorders
Stony Brook Medicine

Dr. Olga Aroniadis is Associate Professor of Clinical Medicine and Chief of the Division of Gastroenterology and Hepatology at Stony Brook University Hospital. Moreover, Dr. Aroniadis is the Director of the Masters in Epidemiology and Clinical Research Program in the Program of Public Health at the Renaissance School of Medicine and the Founder and Director of the Gastrointestinal Women’s Health Center at Stony Brook.

Dr. Aroniadis' clinical practice is largely centered around disorders of gut-brain interaction and gastrointestinal health as it relates to women. Her research interests include studying the influence of patient-perceived stigma on patient engagement and healthcare utilization among patients with disorders of gut-brain interaction; and the effects microbial therapeutics on gastrointestinal diseases, both irritable bowel syndrome and C. difficile infection for which she has received NIH-funded KL2 career development award. Dr. Aroniadis serves on the Educational Affairs Committee of the American College of Gastroenterology (ACG). She is also the Course Director for the biannual ACG Imaging and Pathology Course.

Dr. Aroniadis completed her undergraduate education at Tufts University and graduated summa cum laude. She obtained her medical degree at Albert Einstein College of Medicine and graduated with a Research Distinction in Gastroenterology. Dr. Aroniadis completed her residency training and chief residency in Internal Medicine at Montefiore Medical Center. She then remained at Montefiore Medical Center for her fellowship in Gastroenterology. To further her training in clinical research, she also obtained a Master's Degree of Clinical Research Methods at Albert Einstein College of Medicine. Dr. Aroniadis was a faculty member at Montefiore Medical Center and subsequently joined the faculty at Stony Brook University in 2019.

Jonathan Buscaglia, MD

Jonathan M. Buscaglia, MD, FASGE, AGAF

Professor of Medicine, Department of Medicine
Chief Medical Officer, Stony Brook University Hospital

Dr. Buscaglia received his undergraduate medical education in 2001 from the University at Buffalo, part of the State University of New York (SUNY) system. He completed medical internship and residency at Montefiore Medical Center in the Bronx, New York. He then completed gastroenterology fellowship and the advanced endoscopy fellowship program at Johns Hopkins Hospital in Baltimore, Maryland. Dr. Buscaglia joined the Department of Medicine faculty at Stony Brook University in 2008, where he is now Chief Medical Officer at Stony Brook University Hospital. While at Stony Brook Medicine, Dr. Buscaglia has served as both Director of Endoscopy, and Director of Advanced or Interventional Endoscopy. In 2012 he initiated Stony Brook University Hospital's first interventional endoscopy training program and inpatient consult service. Additionally, Dr. Buscaglia served as Division Chief of Gastroenterology and Hepatology from 2016 to 2022.

Dr. Buscaglia is past President of the New York Society for Gastrointestinal Endoscopy (NYSGE), and has been recognized in New York Magazine and by Castle Connolly as one of the region's Top Doctors. He is a nationally recognized expert in the field of advanced endoscopy, and serves as the senior associate editor for the American Gastroenterological Association's (AGA) official clinical journal, Clinical Gastroenterology and Hepatology. He has also been heavily involved in several national committees within the American Society for Gastrointestinal Endoscopy (ASGE).

Within the field of GI endoscopy, Dr. Buscaglia specializes in pancreatic-biliary diseases and the management of GI tract neoplasia, such as Barrett's esophagus and advanced adenomas of the colon. He has conducted pioneering research in natural orifice transluminal endoscopic surgery (NOTES), therapeutic endoscopic ultrasound (EUS), and more recently in the area of pancreatic cancer for which he has received external grant funding. His research interests continue to focus on personalized medicine in the management of pancreatic cancer.

Dr. Michael Clores, DOMichael J. Clores, DO

Assistant Professor, Department of Medicine
Medical Director of Ambulatory GI

Director of Hepatology

Dr. Michael J. Clores is an Assistant Professor of Clinical Medicine in the division of Gastroenterology and Hepatology at Stony Brook Medicine. Dr. Clores obtained a Bachelor of Arts in Psychology with a pre-medical concentration at the College of the Holy Cross. He obtained his medical degree from the University of New England College of Osteopathic Medicine (UNECOM). He subsequently completed his Internal Medicine Residency and Gastroenterology Fellowship training at Stony Brook University Hospital. His practice encompasses both General Gastroenterology and Hepatology, and he treats a variety of disorders including Gastroesophageal Reflux Disease (GERD), Peptic Ulcer Disease, Irritable Bowel Syndrome (IBS), Small Bowel Malabsorption disorders, Gastrointestinal Bleeding, Colon Polyps, Viral Hepatitis, Non-alcoholic Fatty Liver Disease, Cirrhosis, Portal Hypertension, Autoimmune Hepatitis, Primary Biliary Cholangitis, and Primary Sclerosing Cholangitis.

Dr. Clores enjoys consulting with his patients in the office setting and values a strong physician-patient relationship. He performs upper endoscopy, colonoscopy, and wireless capsule endoscopy. He also performs and interprets Transient Elastography, a non-invasive technique used to quantify liver fibrosis and steatosis.

DesaiDeepak Desai, MD

Assistant Professor of Medicine, Veteran’s Affairs Medical Center Northport
Chief, Division of Gastroenterology and Hepatology, Veteran’s Affairs Medical Center Northport

Dr. Desai previously served as the Associate Chair of Medicine at North Shore University Hospital, Northwell Health in addition to the Divisional Director of Quality and sole GI Hospitalist on the Northwell full time academic faculty. Dr Desai’s interests include management of acute GI/hepatic disease processes, endoscopic management of GI bleeding, medical education and quality management / research. He completed GI Fellowship training at the University of Miami and Medicine Residency and Chief Residency at SUNY Stony Brook.

Lionel S. D’Souza, MDLionel S. D’Souza, MD

Assistant Professor, Department of Medicine
Chief of Endoscopy

Dr. D’Souza is an Assistant Professor of Medicine, Division of Gastroenterology and Hepatology at Renaissance School of Medicine. He is a member of the Advanced Diagnostic and Therapeutic Endoscopy team at Stony Brook University Hospital with expertise in pancreatic diseases, biliary tract diseases and malignant and pre-malignant tumors of the gastrointestinal tract. He specializes in endoscopic retrograde cholangiopancreatography (ERCP), diagnostic and therapeutic endoscopic ultrasound (EUS), endoscopic mucosal resection (EMR) and endoluminal stent placement.

Dr. D’Souza has a special interest in advanced minimally invasive endoscopic techniques such as endoscopic submucosal dissection (ESD), peroral endoscopic myotomy (POEM) and endoscopic suturing and their applications in the resection of cancerous and pre-cancerous lesions of the GI tract as well as in the management of achalasia, gastroparesis, obesity and gastroesophageal reflux disease (GERD).

Alexandra Guillaume, MDAlexandra Guillaume, MD

Assistant Professor, Department of Medicine
Director, Gastrointestinal Motility Center

Dr. Guillaume is a board-certified gastroenterologist with expertise in motility disorders of the gastrointestinal tract. She leads the Stony Brook University Hospital Gastrointestinal Motility Center which specializes in the diagnosis and management of feeding and swallowing disorders as well as luminal motility disorders involving diarrhea and/or constipation, refractory GERD, irritable bowel syndrome and small intestinal bacterial overgrowth. Under the leadership of Dr. Guillaume, the motility center provides high resolution esophageal and anorectal manometry, esophageal pH testing, hydrogen breath tests, as well as Smart Pill.

Dr. Guillaume graduated from the Tufts University School of Medicine. She then completed Internal Medicine residency at New York University Medical Center prior to joining the GI fellowship program at Stony Brook University Hospital. She also has additional fellowship training in the management of enteral and parenteral nutrition from NY Presbyterian Hospital - Columbia University Medical Center.

Daniel S. Jamorabo, MDDaniel S. Jamorabo, MD

Assistant Professor, Department of Medicine

Dr. Jamorabo completed his undergraduate studies in 2008 with a degree in Chemistry cum laude from Williams College. He was selected as a Fulbright Scholar through the United States Department of State to investigate heroin addiction and rehabilitation resources in Coast Province, Kenya from 2009 to 2010. He then began his medical studies at the Warren Alpert Medical School of Brown University, where he graduated in 2014.

Dr. Jamorabo completed his internal medicine internship at the University of Massachusetts Memorial Medical Center in 2015 and residency at Rutgers-Robert Wood Johnson in 2017. He went on to do his fellowship in gastroenterology at New York-Presbyterian Brooklyn Methodist Hospital in 2017 before joining the Department of Medicine faculty at Stony Brook Medicine in 2020.

Dr. Jamorabo specializes in general gastroenterology as well as in pre-transplant hepatology. His research interests include sex and racial inequities within medicine, and quality improvement in medical training and interventions. He is an active member of several national gastroenterology associations and is an active reviewer for several journals.


Mohammad I. Khan, MD, MBBS

Assistant Professor, Department of Medicine

Dr. Khan is a Clinical Assistant Professor of Medicine, Division of Gastroenterology and Hepatology at Renaissance School of Medicine at Stony Brook University. Dr. Khan is a Gastroenterology Hospitalist caring for acutely ill patients with GI disorders on the Inpatient service and providing inpatient procedural services. 



Asim Khokhar, MDAsim S. Khokhar, MD

Assistant Professor, Department of Medicine

Dr. Khokhar joined Stony Brook in 2008 as an Assistant Professor in the Department of Medicine, Division of Gastroenterology. He led the Hepatology section and helped build it as Suffolk county's major tertiary referral site for the treatment of Hepatitis C and management of patients with advanced liver disease. He has been featured as a top doctor in the New York metro area in Newsday and Castle Connolly guide for several years.

He has been actively involved in the research and education front as well, training and teaching GI fellows, medicine residents and medical students at the Renaissance School of Medicine at Stony Brook. He received the teacher of the year award in the division of Gastroenterology for two years in a row and was appointed the Director of Stony Brooks ACGME accredited Gastroenterology & Hepatology fellowship program in 2013, where he oversaw the training and recruitment of a large number of fellows. He served as the program director until 2017, when he decided to take time off to obtain further training in advanced / interventional endoscopy at Memorial Sloan-Kettering Cancer Center.

On his return to the GI division at Stony Brook, Dr. Khokhar is now part of the interventional GI service, which is Suffolk county's major tertiary referral site for the care of advanced and pancreatico-biliary diseases. He splits his time between Stony Brook University Hospital and Stony Brook's teaching affiliate Northport VA Medical Center, where he is tasked to develop their interventional GI services. His research and clinical interests include Interventional Endoscopy, general GI and Hepatology.

Ellen Li, MD, PhDEllen Li, MD, PhD

Director of GI Translational Research

Dr. Li is a board-certified gastroenterologist and world-class scientist with expertise in inflammatory bowel diseases (IBD). Her specialty as a scientist is in translational research, which focuses on taking scientific discoveries and translating them into ways to help improve people’s health. In Stony Brook’s Division of Gastroenterology and Hepatology, she leads a major translational research initiative to analyze the effects of two key genes on the microscopic bacteria (microbia) that are present in the lining of the intestines and to explore how these microbia interact with the lining in the gut.

Dr. Li is a Professor of Medicine and Molecular Genetics and Microbiology, Division of Gastroenterology and Hepatology, at Renaissance School of Medicine.

Farah Monzur, MDFarah Monzur, MD

Assistant Professor, Department of Medicine
IBD Specialist, Program Director GI Fellowship

Dr. Monzur is a board-certified gastroenterologist and hepatologist with expertise in Crohn’s disease and ulcerative colitis. She completed her undergraduate and medical school training as a part of the joint 7-year Accelerated BS/MD program between Rensselaer Polytechnic Institute and Albany Medical College. Subsequently, she went to Georgetown University Hospital for internal medicine residency. She then finished her gastroenterology fellowship at Stony Brook University Hospital.

Dr. Monzur currently is an Assistant Professor of Clinical Medicine at the Division of Gastroenterology and Hepatology. She is the Associate Program Director for the gastroenterology fellowship and is a part of the Master Educator Fellowship Program at Stony Brook University. Dr. Monzur specializes in treating patients with inflammatory bowel disease (IBD), celiac disease, eosinophilic esophagitis, lymphocytic colitis, collagenous colitis, diverticulitis, gastroesophageal reflux disease (GERD), Barrett’s esophagus, peptic ulcer disease, irritable bowel syndrome (IBS), gastrointestinal bleeding, and colon cancer screening. She performs upper endoscopy, colonoscopy, chromoendoscopy, and wireless capsule endoscopy.


Peter L. Shue, MD

Assistant Professor, Department of Medicine
GI Fellowship Site Director at the Northport VA Hospital

Dr. Shue completed his medical education at the New York University School of Medicine. He subsequently completed internal medicine residency at New York University Medical Center and gastroenterology fellowship at Temple University Hospital. Dr. Shue joined the Northport Veterans Affairs Medical Center in 2020 and serves as the GI fellowship site director at the VA Hospital.

Dr. Shue specializes in the diagnosis and management of gastroesophageal reflux disease, Barrett’s esophagus, GI motility disorders and functional bowel disorders. He performs upper endoscopy, colonoscopy, wireless capsule endoscopy, radiofrequency Barrett’s ablation, esophageal manometry and ambulatory pH testing.

Vincent W. Yang, MD, PhDVincent W. Yang, MD, PhD

Professor and Simons Chair, Department of Medicine

Dr. Yang received his gastroenterology fellowship training at the Johns Hopkins Hospital and has close to 25 years of experience in practicing gastroenterology. Prior to joining Stony Brook, Dr. Yang was Director of the Division of Digestive Diseases at Emory University in Atlanta, Georgia. Dr. Yang is an internationally renowned physician scientist with a special interest in the causes, treatment and prevention of colon cancer. Clinically he specializes in treating patients with hereditary (inherited) forms of colon cancer or polyps, including familial adenomatous polyposis (FAP) and Lynch syndrome. He also sees patients with general gastrointestinal conditions, including inflammatory bowel disease, esophageal reflux and chronic diarrheal diseases as well as provides screening tests for colon cancer.


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