Small bowel video capsule endoscopy in Crohn's disease: What have we learned in the last ten years?

Since its introduction in 2001, capsule endoscopy (CE) has become the most important advance in the study of small bowel disease, including Crohn's disease (CD). This technique has been demonstrated to be superior to all other current forms of radiological investigation in detecting mucosal abnormalities of small bowel nonstricturing CD. CE has proven to be extremely useful in diagnosing CD in patients with inconclusive findings from ileocolonoscopy and x-ray-based studies. Almost half of all patients with CD involving the ileum also present lesions in proximal intestinal segments, with the small bowel being exclusively involved in up to 30% of all CD cases. Despite the widespread use of CE, several questions concerning the utility of this technique remain unanswered. The lack of commonly agreed diagnostic criteria for defining CD lesions with the aid of CE may have had an influence on the variation in diagnostic results for CE reported in the literature. The utility of CE in monitoring CD and in guiding therapy has also been proposed. Furthermore, CE could be a useful second-line technique for patients with an established diagnosis of CD and unexplained symptoms. Finally, as no threshold for CD diagnosis has been agreed upon, a severity scale of mucosal disease activity has not been universally followed. None of the available activity indexes based on CE findings has been independently validated. This article discusses several cutting-edge aspects of the usefulness of CE in CD 10 years after its introduction as a sensible method to study the small intestine.