[Characteristics of Crohn's disease under 
double balloon enteroscopy].

To observe ulcer characteristics of Crohn's disease under double balloon enteroscopy, and to evaluate the correlation between endoscopic severity and clinical manifestations.
 Methods: A prospective, observational study from July 2015 to December 2016 in the Third Xiangya Hospital, Central South University, we selected 45 patients with positive double-balloon enteroscopy (DBE) and confirmed Crohn's disease. Two digestive internal physician observed the ulcer characteristics of Crohn's disease under double balloon enteroscopy, and gave a simple endoscopic score for CD (SES-CD). We analyzed the correlation between SES-CD and Crohn's disease activity index (CDAI).
 Results: DBE indicated 24 patient ulcers (53.33%) locating at the end of the ileum, 5 (11.11%) locating at ileocolon, 16 (35.56%) locating at upper gatrointestinal tract and they did not affect the end of the ileum. Among them, 8 cases (17.78%) affected only jejunum. Thirty-two patients with longitudinal ulcers in Crohn's disease, accounting for 71.11%. There was no correlation between SES-CD score and CDAI score (r=0.237, P=0.136).
 Conclusion: The ulcerative appearance in Crohn's disease were diverse under double balloon enteroscopy. Crohn's disease could only affect the upper gastrointestinal tract or jejunum. The unwounded ileum and ileocecal valve couldn't be a sign to exclude Crohn's disease. CDAI score couldn't fully assess the prognosis of Crohn's disease.