Crohn disease (CD) is a chronic inflammatory bowel disease that affects the entire gastrointestinal tract but is most frequently localized to the large and small bowel. Small bowel endoscopy helps with the differential diagnosis of CD in suspected CD patients. Early diagnosis of CD is preferable for suspected CD conditions to improve chronic inflammatory infiltrates, fibrosis. Small bowel endoscopy can help with the early detection of active disease, thus leading to early therapy before the onset of clinical symptoms of established CD. Some patients with CD have mucosal inflammatory changes not in the terminal ileum but in the proximal small bowel. Conventional ileocolonoscopy cannot detect ileal involvement proximal to the terminal ileum. Small bowel endoscopy, however, can be useful for evaluating these small bowel involvements in patients with CD. Small bowel endoscopy by endoscopic balloon dilation (EBD) enables the treatment of small bowel strictures in patients with CD. However, many practical issues still need to be addressed, such as endoscopic findings for early detection of CD, application compared with other imaging modalities, determination of the appropriate interval for endoscopic surveillance of small bowel lesions in patients with CD, and long-term prognosis after EBD.