Technical Abstract: Inflammation is the progression of vascular changes in response to injury leading to accumulation of fluids and leukocytes in the extracellular space. Endothelial cell activation leads to an increased permeability of capillaries and venules resulting in leakage of fluids and leukocytes from these small vessels. Trauma, toxins, or chemical mediators such as cytokines, histamine, leukotrienes, bradykinins elicit activation of endothelial cells. While inflammation is fundamentally a protective response, excessive inflammation may result in hypersensitivity, fibrosis, or other harmful reactions. Within the intestinal mucosa, a physiologic steady state between reactivity to luminal antigens and down regulation of inflammation provides protection and gut homeostasis, respectively. Stimulation with certain microbes and/or their toxins may alter this balance resulting in inflammatory diseases of the bowel.