The main objective of this study is to determine the role of epithelial cell homeostasis in the pathogenesis of intestinal diseases. Background: Alterations in intestinal barrier function may play a significant role in the pathogenesis of chronic intestinal diseases such as inflammatory bowel disease (IBD). The intestinal epithelium functions as a barrier to the luminal contents, thereby preventing undesirable solutes, micro-organisms and other luminal antigens from entering the body. Confocal endomicroscopy has recently been shown that increased epithelial cell shedding may contribute to increased intestinal permeability, at least locally. In our study, we want to determine the contribution of epithelial cell shedding to intestinal permeability in vivo in patients with inflammatory bowel disease compared to controls. Scope: In inflammatory bowel disease patients and controls (patients undergoing endoscopy for other indications). Methods: We will perform confocal endoscopy during the patient's endoscopic procedure. Procedure: The patient will receive intravenous fluorescein, followed by confocal imaging of the gastrointestinal tissue. The images are captured on the computer. The proposed study will provide important insights into epithelial cell shedding as a contributor to altered intestinal permeability.