Angelo Bartolo Biviano, MD

Dr. Francisco Guzman-Pruneda is an Assistant Professor of Surgery at Columbia University Medical Center. He is the Associate Program Director for the Minimally Invasive and Bariatric Surgery Fellowship Program, and the Surgical Director for the Gastroparesis program at Columbia University. He is Board Certified in Surgery by the American Board of Surgery, and is a member of the American Society for Metabolic and Bariatric Surgery. He completed his Medical School training in Monterrey, Mexico, his residency in General Surgery at Brigham and Women's Hospital and The Ohio State University Wexner Medical Center, and a fellowship in Bariatric Surgery at Mount Sinai in New York City. In addition, Dr. Guzman-Pruneda completed two research fellowships: in Immunology at the University of Texas M.D. Anderson Cancer and in Pediatric Surgery at Texas Children's Hospital (Baylor College of Medicine), and a Global Surgery Exchange Program in Sydney, Australia.Dr. Guzman’s practice focuses on minimally invasive (laparoscopic & robotic) bariatric and foregut surgery. In addition to performing first-time weight loss operations, a significant part of his practice includes revisional or corrective surgery to address problems with previous bariatric operations. From a foregut surgery perspective, he performs hiatal / paraesophageal hernia repairs and anti-reflux surgery. Additional areas of expertise include peritoneal dialysis access surgery and is leads the surgical management for advanced gastroparesis patients that fail to respond to medical therapy, including implantation of Enterra gastric stimulator device.

Dr. Ramsay Fuleihan is the clinical director of the Division of Pediatric Allergy, Immunology and Rheumatology and a professor of pediatrics at Columbia. Throughout his career his main research interest has been the pathogenesis and treatment of primary immunodeficiency diseases. Dr. Fuleihan was formerly chief of the division of allergy and immunology at Sidra Medical and Research Center in Qatar, and Director of Primary Immunodeficiency Clinical Services and the Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies at Ann & Robert H Lurie Children’s Hospital of Chicago. Dr. Fuleihan earned his medical degree from the American University of Beirut in Lebanon, completed his pediatric residency at Duke University Medical Center, and fellowship in allergy and immunology at the Children’s Hospital-Boston at Harvard Medical School. Dr. Fuleihan is a member of the Board of Directors of the American Board of Allergy and Immunology. He is an active fellow of the American Academy of Allergy Asthma and Immunology, where he served as Chair of the Primary Immunodeficiency Committee; a member of the Clinical Immunology Society, where he served as chair of the CME committee; a member of the European Society for Immunodeficiencies; and a member of the Society for Pediatric Research. He serves on the Medical Advisory Committee of the Immune Deficiency Foundation and on the Board of Directors of Bounce Children’s Foundation.

Dr. Lebwohl is a graduate of Harvard College, where he majored in music. He received his MD from Columbia College of Physicians and Surgeons in 2003, and then completed his internship, residency, and chief residency in internal medicine at Columbia. He stayed at Columbia as a fellow in Digestive and Liver Disease, during which time he obtained a Master's in Patient Oriented Research from the Department of Biostatistics at the Mailman School of Public Health. He was a post-doctoral fellow in a National Cancer Institute-funded Training Program in Cancer-Related Population Sciences under the mentorship of Alfred Neugut. He joined the faculty of the Celiac Disease Center at Columbia University in 2010. Dr. Lebwohl is a past president of the Society for the Study of Celiac Disease, and is the Director of Clinical Research at the Celiac Disease Center at Columbia University, where he collaborates with investigators in the United States and abroad in epidemiology, patterns of care, natural history, and therapeutics. Dr. Lebwohl's second and related research interest is quality of endoscopy, including improving the detection of colorectal adenomas. He has co-authored more than 350 peer-reviewed publications. His research is supported by the National Institutes of Health, and past research funding includes the American Gastroenterological Association, the Celiac Disease Foundation, and the American Scandinavian Foundation. Dr. Lebwohl served on the Gastrointestinal Drugs Advisory Committee of the United States Food and Drug Administration (2017-2025), including a term as Chair. He is heavily involved in medical education and lectures regularly to trainees on topics including celiac disease, evidence-based medicine, clinical decision making, pseudoscience, diarrhea, the Beethoven string quartets, and colorectal cancer screening.