BACKGROUND: Patients with inflammatory bowel disease (IBD) have proven an increased risk of venous thromboembolism (VTE), particularly when hospitalized. The estimate of the true risk varies considerably between studies, primarily due to differences in methodology. We set out to determine the incidence of VTE in a population-based European inception cohort.

METHODS: IBD patients were incepted into a cohort that was prospectively followed from the early 1990s to the early 2000s. A total of 1145 patients were followed for a total of 10,634 patient-years (p.y.).

RESULTS: A total of 19 thromboembolic events were identified - 13 deep vein thrombosis and 6 with pulmonary embolism. The incidence rate of VTE was 1.8 per 1000 p.y.

CONCLUSION: The risk of VTE was elevated in this IBD cohort but lower than previously reported. The highest risk was seen in hospitalized patients, but corticosteroids-requiring disease in outpatients also conferred some risk.