The points at issue concerning diagnostic criteria for Crohn's disease - From the standpoint of clinicians

To clarify the points at issue concerning diagnostic criteria for Crohn's disease (CD), we analyzed the clinical course of 15 patients with aphthoid colitis, which was difficult to distinguish from CD. Five of 7 (71%) patients, who were suspected of CD at the initial colonoscopy, progressed to definite CD, but only one (13%) of 8 patients with aphthoid colitis progressed to definite CD. This result indicates that the present criteria are useful for the diagnosis of CD. Most of the patients, who progressed to defined CD, were diagnosed for CD because of the histological detection of granulomas. However, the positive rates for granulomas per biopsied specimens were relatively low even in these CD patients. Four of 5 patients, who had progressed to CD, had past histories of anal lesions. Interestingly, two of these patients had recurrent perianal fistula or abscess before the appearance of longitudinal ulcers or granulomas. To diagnose CD in the earlier stage, it is necessary to improve the detection of granuloma by observing the serial sections, and to investigate new histopathological findings for diagnosis and to add the findings of anal lesions to the diagnostic criteria as accessory findings.