Dr. Yong Sik Yoon is a colorectal surgeon and an associate professor at the Department of Surgery of the University of Ulsan College Medicine (UUCM). He is certificated by the Korean Board of Surgery and the Korean Society of Coloproctology. He earned his medical degree from UUCM. He completed his internship, residency, and fellowship at the Asan Medical Center (AMC), which is an educational hospital of UUCM. From 2010, he started his own practice as clinical assistant professor at AMC. Until these days, he has done more than 3000 surgical cases of colorectal disease. He has been interested in surgical treatment of inflammatory bowel disease (IBD) and robot-assisted surgery. He was a former general secretary of IBD study group, Korean Society of Coloproctology.