Our Physicians

Dr. Robert Venick is a Professor and Interim Chief and Director Pediatric Liver and Intestinal Transplant Programs at The David Geffen School of Medicine at UCLA. Dr. Venick has been a part of the intestinal failure, liver and intestinal transplant teams at UCLA over the past decade. His clinical and translational research in intestinal failure has focused on nutritional outcomes and the role of Omega-3 Fatty Acids in intestinal failure associated liver disease. 

Dr. Sue McDiarmid is a Distinguished Professor of Pediatrics and Surgery, Associate Fellowship Program Director and Assistant Program Director of  Pediatric Liver and Intestinal Transplant Programs at the David Geffen School of Medicine at UCLA. 

Dr. Chan is a Clinical Instructor at UCLA. Dr. Chan earned his BS in Bioengineering from UC Berkeley and MPH from Harvard Chan School of Public Health. He received his MD from UC Irvine. He completed both his pediatric residency and pediatric gastroenterology fellowship at UCLA. During fellowship, Dr. Chan joined the UCLA Specialty Training and Advanced Research (STAR) program while pursuing his Ph.D. in Molecular, Cellular & Integrative Physiology. Dr. Chan joined the UCLA faculty in 2023.

Dr. Hamandi received his medical degree from the University of Virginia. He completed his residency at Case Western Reserve University, and his fellowship in pediatric gastroenterology, hepatology, and nutrition at The Johns Hopkins University.

He joins UCLA after starting his career at UCSF, where he served as the clinical director of the Pediatric Inflammatory Bowel Disease (IBD) Program. Additionally, he has authored important academic papers and advanced numerous clinical trials in the field.

Dr. Marjorie-Anne Guerra Manchandia is Staff Physician at The David Geffen School of Medicine at UCLA. Dr. Manchandia received her medical degree from Yale School of Medicine. She completed her residency in pediatrics and her fellowship training in pediatric gastroenterology at UCLA Medical Center. Dr. Manchandia's clinical interests include general gastroenterology, nutrition support, intestinal failure, transplantation.

Dr. Elizabeth Marcus is an Assistant Professor of Pediatrics and Fellowship Director at The David Geffen School of Medicine at UCLA. She received a BA in Psychology from Stanford University and her medical degree from the University of Southern California. She completed her residency in Pediatrics at Children's Hospital of Los Angeles and her fellowship in Pediatric Gastroenterology at UCLA. Her clinical interests include intestinal failure/intestinal transplant, TPN, and general GI.

Dr. Martín G. Martín is a Professor of Pediatrics in The David Geffen School of Medicine at UCLA. He received his medical degree and a Master of Public Policy from Harvard and completed his residency in Pediatrics at Harbor-UCLA Medical Center and his fellowship in Pediatric Gastroenterology at UCLA. His clinical interest is in translational research in Pediatric Intestinal Failure, including chronic diarrheal disorders and intestinal pseudo-obstruction.

Dr. Pathak a staff physician who is passionate about keeping her patients healthy and increasing community outreach to provide better subspecialized care to children in need. Her clinical and research interests include gastroenterology, nutrition: total parenteral nutrition and enteral feeding, fatty liver disease, eosinophilic esophagitis, celiac disease, gastroesophageal reflux disease, and functional gastrointestinal disorders.

Dr. Jorge Vargas is Professor of Pediatrics at The David Geffen School of Medicine at UCLA and is the Medical Director for the Parenteral and Enteral Nutrition Support Program at Ronald Reagan UCLA Medical Center. Dr. Vargas received his medical degree from Colegio Mayor de Nuestra Señora del Rosario in Bogota, Colombia.

Dr. Emily Whang joined the Division of Pediatric Gastroenterology, Hepatology and Nutrition in July of 2017 upon completion her Pediatric Gastroenterology Fellowship at UCLA Mattel Children’s Hospital. Dr. Whang received her medical degree from the Loma Linda University School of Medicine and completed her pediatric residency training at Loma Linda University Medical Center.

Jonathan C. Lebowitz, MD is a health sciences assistant clinical professor of pediatrics at the David Geffen School of Medicine at UCLA. Dr. Lebowitz earned his BA from New York University with a major in Journalism and Psychology and his MD from the NYU Grossman School of Medicine.

Dr. Schenker is a Health Sciences Assistant Clinical Professor of Pediatrics at the David Geffen School of Medicine at UCLA. Dr. Schenker earned her BA degree from Tufts University with a major in biology, and her MD from the University of California, San Francisco (UCSF). She completed her residency training in pediatrics at UCSF and her subspecialty training in Pediatric Gastroenterology at Children's Hospital Los Angeles.