Background: Faecal calprotectin (FC) is an accurate biomarker of disease activity in inflammatory bowel disease (IBD), yet the cost/resource implications of incorporating FC into 'real-world' practice remain uncertain., Aim: To evaluate the utility of FC in clinical decision-making and on healthcare costs in IBD., Methods: Retrospective data, including colonoscopy/other investigations, medication, admission and surgical data, were collected from hospital records and compared between two groups: pre-FC historical cohort (2005-2009) where colonoscopy was used to assess IBD activity versus the cohort where FC was used first instead (2010-2014). Post-test costs were also compared., Results: A total of 357 FC tests (246 patients, 2010-2014) and 450 colonoscopies (268 patients, 2005-2009) were performed. On subsequent review, both FC and colonoscopy (in their respective cohorts) were associated with changes in management in 50.7 versus 56.2% (P = 0.14), respectively, with similar proportions of subsequent IBD-related investigations within 6 months (21.8 vs 21.9%, P = 1.0). Prior to FC availability (2005-2009), a colonoscopy for disease reassessment cost AU$606 578 (cost per patient-year $1887.34) versus AU$282 048 (cost per patient-year $968.60) when FC ± colonoscopy was used (2010-2014). Within the FC cohort, 73.6% did not proceed to colonoscopy within 6 months post-FC, and 60.6% had not undergone colonoscopy post-FC by the end of follow up (median 1.8 years (0.1, 4.6) post-FC). Those with FC ≥ 250 were scoped earlier than those with FC < 100 μg/mL (median 0.49 vs 1.0 years, P = 0.03)., Conclusion: Introduction of FC into routine IBD care aided changes in clinical management in a similar proportion, yet at potentially half the total cost, compared to a historical colonoscopy-only cohort at the same centre., (© 2018 Royal Australasian College of Physicians.)