Dr. Siwiec is a board-certified gastroenterologist with expertise in disorders of gut-brain interaction, esophageal motility disorders, gastroparesis, and small intestinal bacterial overgrowth. He completed his undergraduate studies at Northwestern University followed by medical school at Rosalind Franklin University of Medicine and Science. He then completed training in internal medicine at Advocate Lutheran General Hospital followed by gastroenterology fellowship at the Medical College of Wisconsin prior to joining the faculty at Indiana University in August 2012. He has served as the section chief for gastroenterology at IU Health North Hospital since 2014 and has been an active physician leader within the IU Health system. In June 2023, he was appointed Service Line Leader for academic gastroenterology at IU School of Medicine and IU Health. He is a fellow of the American Gastroenterological Association and an active member of the American College of Gastroenterology and the American Neurogastroenterology and Motility Society.