The course of Inflammatory Bowel Disease (IBD incorporating both Crohn’s Disease and ulcerative colitis) varies substantially between affected individuals, but reliable prognostic markers are not available in clinical practice. This hinders disease management because patients with aggressive disease will be undertreated by conventional “step-up” therapy, while those with indolent disease would be exposed to the risks and side-effects of unnecessary immunosuppression if a “top-down” approach was indiscriminately used.