Dr. Sun is Board Certified in Internal medicine and completed his Gastroenterology Fellowship at Stony Brook Medical Center. He is a practicing Gastroenterologist at both Stony Brook Medical Center and at the Northport Veterans Affairs Medical Center. At Stony Brook, Dr. Sun has thrived in his role as a Gastroenterology Hospitalist caring for acutely-ill patients with GI disorders on the Inpatient service. Dr. Sun specializes in treating patients with upper and lower GI bleeding, abdominal pain, dysphagia, diarrhea, and acute liver injury.