To idetify the factors favoring the use of enteral nutrition would be helpful to select preferred patients suitable for enteral nutrition.

Crohn's disease (CD) is a chronic, transmural inflammatory disorder affecting the whole alimentary tract from mouth to anus. Over the past decades, the incidence of CD is either high and stable or low but rising in the worldwide. Although the precise etiopathogenesis of CD remains unknown, a number of lines of evidence showed that inappropriate diet was one of the reasons responsible for the onset of CD, and diet therapy has been gaining increasing attention in the therapeutic work-up of CD.

Due to reduced intake and high intestinal losses, over three quarters of CD patients would suffer weight loss. Involvement of small bowel in CD patients made their nutrition status much poorer than ulcerative colitis (UC) patients. Therefore, nutrition support is of great value in the management of CD. It is widely accepted that enteral nutrition could help pediatric CD patients to reach clinical and endoscopic remission, with similar efficacy but less side effects than corticosteroids. However, the value of enteral nutrition in adult active CD is still controversial, with an unstable remission rates ranging from 8% to 100%. Varied characteristics and compliance of enrolled patients might explain this wide range. Considering this, idetification of factors favoring the use of enteral nutrition would be helpful to select preferred patients suitable for enteral nutrition.

In this study, we will observe the role of enteral nutrition in active adult CD. The age, gender, serum CRP, albumin, fecal calprotectin, nutritional risk screening 2002 (NRS2002), involved intestinal segments and other items will be correlated with the changes of Crohn's disease activity index (Best CDAI) and CRP in order to idetify the factors favoring the use of enteral nutrition.

Inclusion Criteria:

• Diagnosed as active CD based on clinical presentation, endoscopic and pathology results
• Has the willing to receive enteral nutrition

Exclusion Criteria:

• No exposure to Glucosteroids or immunosuppressions
• Complete intestinal obstruction

Active crohn's disease patients from the clinics and wards in the Second Affiliated Hospital, Zhejiang University