Inflammatory bowel disease (IBD) is a chronic and idiopathic inflammatory disease of the gastrointestinal tract that shows an episode of remission and recurrence. Ulcerative colitis (UC) and Crohn's disease (CD) are the two main forms of inflammatory bowel disease. The number of IBD patients has increased rapidly in recent years and is increasingly prominent in Korea. However, many physicians still do not fully understand the clinical and endoscopic features of inflammatory bowel disease, so diagnosis is often delayed or inaccurate in many cases.