Capsule Endoscopy for Differentiating Early Crohn's Disease from Behçet's Disease

Objective: Crohn's disease (CD) and Behçet's disease (BD) are two major causes of inflammatory lesions in the small bowel. For detecting such lesions, the most sensitive exam is small-bowel capsule endoscopy (CE), an imaging modality suitable for evaluating lesions of the small intestine, with a relatively low rate of capsule retention. However, few reports have employed CE to compare the small-bowel inflammation in early CD with that in early BD. Thus, the aim of our study was to obtain a systematic characterization of small-bowel lesions in early CD and BD by using CE. Methods: This retrospective single-center study included 22 patients with early CD and 16 patients with early BD. The patients underwent small-bowel CE for detection and characterization of small-bowel lesions. After reviewing the CE findings in each patient, we assessed the small-bowel mucosal inflammation using the Lewis score, an inflammatory biomarker (C-reactive protein), and the disease activity index. The CE findings (number, distribution, and shape of lesions), Lewis score, disease activity index, and C-reactive protein levels were compared between the groups of CD and BD patients. Results: Small-bowel lesions were observed in 90.9% of CD patients, and in 68.7% of BD patients. Regarding distribution, CD patients exhibited multiple concentrated ulcers, which were more severe distally, while BD patients mostly exhibited solitary ulcers. Regarding shape, linear and longitudinal ulcers were observed, respectively, in 68.2% and 50% of CD patients; however, no such ulcers were observed in BD patients. C-reactive protein levels and disease activity indices were poorly correlated with Lewis score for both diseases. Capsule retention during CE did not occur in any patient included in this study. Conclusion: CE is a valuable tool to assess the mucosal inflammation of the small bowel in early CD and BD. Greater mucosal inflammation in the distal small bowel, and presence of linear and longitudinal ulcers may be the key findings for the differential diagnosis of small-bowel inflammation between early CD and BD.