Different clinical outcomes in Crohn's disease patients with esophagogastroduodenal, jejunal, and proximal ileal disease involvement: is L4 truly a single phenotype?

Background: The Montreal classification defines L4 Crohn's disease (CD) as any disease location proximal to the terminal ileum, which anatomically includes L4-esophagogastroduodenal (EGD), L4-jejunal, and L4-proximal ileal involvement. L4-jejunal disease was established to be associated with poor prognosis. However, the outcome of patients with L4-proximal ileal disease or L4-EGD remains to be clarified.

[The prevalence and characteristics of anemia in Crohn's disease in the Chinese].

Objective: To investigate the prevalence and characteristics of anemia among patients with Crohn's disease (CD) in Chinese population and identify the possible risk factors.

Methods: A cross-sectional study was performed in 441 patients with CD enrolled from the First Affiliated Hospital of Sun Yat-Sen University between January 2003 and May 2012. The prevalence, severity, type of anemia in these patients was assessed when diagnosis was confirmed.