The pathophysiology of inflammatory bowel disease (IBD) includes leukocyte infiltration, blood and lymphatic remodeling, weight loss and protein enteropathy. The roles of angiopoietin-2 (Ang-2) in initiating gut inflammation, leukocyte infiltration and angiogenesis are not well understood. Several important differences were seen in the development of experimental IBD in Ang-2-/- mice. Although weight change and disease activity differ only slightly in WT and Ang-2-/- + DSS treated mice, leukocyte infiltration, inflammation and blood and lymphatic vessel density is significantly attenuated compared to WT+ DSS mice. Gut capillary fragility and water export (stool blood and form) appear significantly earlier in Ang-2-/- + DSS mice vs. WT. Colon lengths were also significantly reduced in Ang-2-/- and gut histopathology was less severe in Ang-2-/-compared to WT + DSS. Lastly, the decrease in serum protein content in WT + DSS was less severe in Ang-2-/- + DSS, thus protein losing enteropathy (PLE) a feature of IBD is relieved by Ang-2-/-. These data demonstrate that in DSS colitis, Ang-2 mediates inflammatory hemangiogenesis, lymphangiogenesis and neutrophil infiltration to reduce some, but not all clinical features of IBD. The implications for Ang-2 manipulation in the development of IBD and other inflammatory diseases and treatments involving Ang-2 are discussed.