Capsule endoscopy appropriateness in Crohn's disease.The incidence of Crohn's disease is steadily growing in western countries and the diagnosis is still delayed from symptoms onset by several years. Up to one third of patients have exclusive disease location in the small bowel, the tract less accessible to conventional diagnostic visualization. In the last decade, astonishing improvements in radiologic and endoscopic imaging allowed to better diagnose small bowel Crohn's disease. In particular, capsule endoscopy is a high sensitive tool in diagnosing subtle inflammatory lesions of the mucosa, but retention risk and low specificity limit its use in this setting. The present review provides a critical evaluation of the published studies addressed to the diagnostic role of small bowel capsule endoscopy in established, suspect, operated Crohn's disease and unclassified inflammatory bowel disease: in an attempt to help the clinician to utilize capsule endoscopy properly in the different clinical scenarios associated to inflammatory bowel disease.