OBJECTIVES: IBS is considered a diagnosis of exclusion based on several laboratory and diagnostics procedures to exclude other organic conditions.  A novel IBS diagnostic blood panel has been developed which tests for the presence of two biomarkers associated with IBS-D.  This analysis estimates the cost impact to the Italian healthcare system by introducing this test into the diagnostic pathway. METHODS: A budget impact model was based on a cost-minimization decision model developed to compare the costs associated with two possible diagnostic pathways: (1) diagnostic pathway with a novel IBS diagnostic blood panel and (2) exclusionary diagnostic pathway and applied to the Italian population 18-65yrs old. Model structure was based on current literature and guidance from IBS expert clinicians.  Direct medical expenses for laboratory tests, diagnostic procedures and visit costs were included in Euros and weighted by utilization rates provided by practicing gastroenterologists in Italy. Indirect cost estimate was based on the literature and only included time off work, adjusted for per capita income in Italy. RESULTS: Colonoscopy, ultrasound and SBFT were the most common diagnostic (instrumental) procedures reported with estimated utilization rates of 50%, 90% and 35%, respectively.  Corresponding charges were €312.50, €70 and €300, respectively.  Estimated total base case charges for the IBS diagnostic panel pathway (assumes 75% of test positive patients receive IBS-D treatment) vs the exclusionary pathway were €1,351 vs €1,425, respectively.  If clinicians use the test 50% of the time for the 50% of the estimated 447,275 people who might have IBS-D who seek treatment, net savings to the Italian healthcare system is €27,581,982.  Cost neutrality occurs if 49% of the “test positive” patients seek IBS treatment. CONCLUSIONS: Inclusion of a novel IBS diagnostic blood panel in the diagnostic pathway has the potential for significant cost savings due to the avoidance of unnecessary testing.