In patients with IBD, endoscopy is becoming an indispensable practice for detecting intestinal lesions reflecting the initiation and the progression of IBD or cancers, which may be associated with IBD lesions. However, given that UC lesions are primarily confined to the colon and the rectum, while CD lesions may appear at any location from the mouth to the perianal region, and inflammation may go beyond the mucosa, endoscopy has limitations in CD patients, but convenient and reliable in UC patients. Although currently, the significance of observing mucosal lesions during an endoscopic examination to assess mucosal condition or determine the severity of IBD is acknowledged, in the near future the endoscopic examination is expected to be performed more appropriately during disease course. This assertion will be supported by the outcomes of future work in this clinical setting, including combination of biomarkers in UC and imaging techniques like CT and MRI in CD.