Capsule endoscopy findings for the diagnosis of Crohn’s disease: a nationwide case–control study

Background: Capsule endoscopy can be used to identify the early stage of small bowel Crohn’s disease (CD). We evaluated significant small bowel capsule endoscopy (SBCE) findings that can lead to early diagnosis of CD. Methods: We retrospectively accumulated clinical and SBCE data of 108 patients (63 with and 45 without CD). Types of small bowel mucosal injuries, including erosion, ulceration, and cobblestone appearance, and the alignment of diminutive lesions were compared between patients with and without CD. Inter- and intra-observer agreement in the determination of lesions was assessed in 25 pairs of SBCE from the two groups. Results: Under SBCE, cobblestone appearance (33% vs. 2%, p < 0.0001), longitudinal ulcers (78% vs. 20%, p < 0.0001), and irregular ulcers (84% vs. 60%, p < 0.01) were more frequently found in patients with CD. Linear erosion (90% vs. 38%, p < 0.0001) and irregular erosion (89% vs. 64%, p < 0.005) were also more frequent in patients with CD. Furthermore, circumferential (75% vs. 9%, p < 0.0001) and longitudinal (56% vs. 7%, p < 0.0001) alignment of diminutive lesions, mainly observed in the 1st tertile of the small bowel, was more frequent in patients with CD. Good intra-observer agreement was found for ulcers, cobblestone appearance, and lesion alignment. However, inter-observer agreement of SBCE findings differed among observers. Conclusions: Circumferential or longitudinal alignment of diminutive lesions, especially in the upper small bowel, may be a diagnostic clue for CD under SBCE, while inter-observer variations should be cautiously considered when using SBCE.