OBJECTIVES: To estimate health care resource use and costs associated with the management and treatment of constipation predominant irritable bowel syndrome (IBS-C) in Spanish clinical practice. METHODS: The 2011 primary care (PC) IASIST database, which includes 3,678,522 clinical charts corresponding to PC sites from the National Health System (NHS), was used to estimate the number of patients with IBS-C (identified by a combination of ICD code and prescription of IBS-C drugs) and obtain data on the number of hospitalizations (service, frequency and duration), scheduled and emergency visits to PC, referrals to specialist care, and IBS-C treatments prescribed and dispensed in retail pharmacies and their associated costs. Based on data from IASIST database and unit costs retrieved from the e-Salud database, health care costs associated with IBS-C from the NHS perspective were calculated.  RESULTS: A total of 5,649 IBS-C patients were indentified in the database, corresponding to a prevalence of 0.15% of patients attending PC. Total costs associated with IBS-C in the sample were estimated to be €4,755,725; highest costs were associated with PC visits (€2,791,725, corresponding to 58.7% of total IBS-C costs). This high cost of PC visits is explained by the high number of visits by IBS-C patients (17.4 visits annually per patient). Costs of PC visits are followed by hospitalization costs (€610,859, 12.8% of total cost), medical visits to specialists (€556,164, 11.7%) and emergency room visits to PC (€491,142, 10.3%). Costs of pharmacological treatment (€305,707) represented only 6.4% of total IBS-C costs. CONCLUSIONS: The low prevalence of IBS-C observed may be due to the under-registration or under-diagnosis of IBS-C. Costs associated with the management of IBS-C are driven mainly by the high number of PC visits, which may be associated with the current unmet medical needs in IBS-C.