The aim of this study is to assess the ability of miR-320a and other specific microRNAs to follow the disease course in patients with Crohn's disease (CD) and ulcerative colitis (UC), and to distinguish both entities, infectious colitis and healthy controls. Furthermore, the accuracy of miRNA-320a to distinguish CD or UC from irritable bowel syndrome (IBS) should be evaluated .

The study is designed as a single center non-randomised prospective trial.

Inflammatory bowel disease (IBD), which comprises Crohn's disease (CD) and ulcerative colitis (UC), is a chronic-remittent disease of the gastrointestinal tract with leading symptoms such as diarrhea, abdominal pain and rectal bleeding. Absence of mucosal inflammation (so called mucosal healing) is a promising treatment target.as it leads to reduction of colectomy rates, hospitalization and need for surgery. However, overtreatment with severe combined immunosuppressive therapy always bears the risk of severe side-effects such as opportunistic infections. To assess the course of disease, clinical evaluation, noninvasive diagnostic or imaging and invasive endoscopic techniques are currently used. As frequent endoscopical monitoring is not always possible, more specific and noninvasive biomarker are needed to monitor disease activity. The commonly used noninvasive biomarkers C-reactive protein and fecal Calprotectin, which are useful to detect disease activity, are limited due to the lacking specificity for IBD and the weak correlation with the extend of disease. Overall the currently available tools to noninvasively follow the course of disease activity do not possess appropriate specificity, sensitivity and cost effectiveness for in- and outpatient clinical monitoring.

Recently, we could demonstrate the potential of miR(microRNA)-320a to monitor disease activity in experimental colitis mouse models.

The aim of this study is to assess the ability of miR-320a and other specific microRNAs to follow the disease course in patients with inflammatory bowel disease as compared to healthy controls, non IBD-colitis and IBS.

The study is planned as a prospective single center study.

Number of patients: 7 groups of 50 patients

• 1: adult CD patients in remission
• 2: adult CD patient with endoscopical proven disease activity
• 3: adult UC patients in remission
• 4: adult UC patient with endoscopical proven disease activity
• 5: adults with infectious colitis (ie. Ischemic, infectious or toxic colitis)
• 6. Adults with IBS
• 7: healthy adults

All eligible individuals are informed about the nature of the study. All individuals provide written informed consent before entering the trial.

Budget:

All procedures in the present study are performed in ordinary patients, with ordinary staff. Therefore, no extra costs occur for personal.

Inclusion Criteria:

• Patients with Crohn's disease or ulcerative colitis
• Control patients: healthy patients or patients with colitis of other origin than Crohn's disease or ulcerative colitis as well as patients with IBS

Exclusion Criteria:

• Age under 18 years
• Pregnancy
• Inability to understand information for participation
• Refusal of participation