 The available clinical measures of ulcerative colitis activity can be overly influenced by functional symptoms. Placebo response rates in clinical trials are high. Several non-invasive biomarkers are currently available for assessing IBD disease activity including erythrocyte sedimentation rate, c-reactive protein and fecal calprotectin. Although these markers hold some promise, their performance is less than ideal. what is needed is a simple, non-invasive biologic measure of UC disease. 