Dr. DeRosa is the Department Head of Gastroenterology and Hepatology at Sansum Clinic, a part of Sutter Health, in Santa Barbara, California. He was the principal investigator at Sansum Clinic for two Cologuard trials evaluating a stool-based assay for a non-invasive modality to screen for colorectal cancer. He has worked as Medical Director of Endoscopic Services at Santa Barbara Cottage Hospital and Director of Pediatric Advanced Interventional Endoscopy. He has researched the most effective preparations for inpatient colonoscopy and alternative non-invasive strategies to treat esophageal foreign body obstructions that have changed the treatment paradigms at his institution.

Dr. DeRosa trained at the UCLA-West LA VA hospital for Internal Medicine and served as Chief Resident before subspecializing in Gastroenterology and Hepatology at UC Irvine. During his training, he co-authored a chapter on Obscure GI Bleeding in Clinic Gastroenterology and Hepatology and published an article in the American Journal of Gastroenterology demonstrating the importance of screening for celiac disease in patients with irritable bowel syndrome.