The purpose of this study is to determine whether urinary PGE-M levels correlate with Ulcerative Colitis Disease activity and to compare how well urinary PGEm correlates with other noninvasive biomarkers of disease activity such as CRP and fecal calprotectin.

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.

Cyclooxygenase-2 (COX-2) is involved in prostaglandin E2 (PGE2) synthesis and is expressed in epithelial inflammatory conditions and some cancers. We have developed an assay to quantify the major urinary metabolite of PGE2, PGE-M. PGE-M has been previously shown to be elevated in the urine of patients with advanced colorectal neoplasia relative to controls. We recently showed that PGEm was a sensitive and specific marker of Crohn's disease activity (Accepted for publication at DDW 2006).

Inclusion Criteria:

• Outpatient male or female 18 years or older
• Confirmed diagnosis of ulcerative colitis
• Informed consent obtained
• Able to give blood, urine and stool samples
• Will undergo a diagnostic colonoscopy of part of routine Ulcerative Colitis care

Exclusion Criteria:

• Unable to give consent
• Crohn's disease
• Does not meet inclusion criteria
• Pregnant