Commonly used biomarkers do not contribute to diagnosing irritable bowel syndrome.

Objective: The aim of this article was to examine the costs and effectiveness of standardized blood and fecal investigations in patients fulfilling the Rome criteria for irritable bowel syndrome (IBS).

Methods: We conducted a real-life cohort study in patients fulfilling the Rome III criteria for IBS without red flag signs or symptoms, in a center of excellence for IBS patients from 1 January 2015 till 1 January 2019. Standardized blood and fecal investigations [hemoglobin (Hb), thyroid-stimulating hormone (TSH), coeliac serology, and fecal calprotectin (FCP)] were performed during the first consultation.