Clinically, Dr. Longman focuses on the care of patients with Ulcerative Colitis and Crohns' disease. His active research focuses on understanding the role for bacteria in inflammatory bowel disease. His work has been published in Nature, Science, Journal of Experimental Medicine, and Blood. For this work, he has received numerous awards as well as funding from both the American Gastroenterological Association and the National Institutes of Health. He has a particular interest in the care of IBD patients with joint pains and serves as a co-investigator on research studies to better understand the underlying cause.