Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is increasing in incidence in many countries of the world, especially in countries were infectious colitis are still prevalent. One challenge of research combining IBD patients from different international centers is the possibility that practice variation may affect the diagnosis and treatment decisions at each country. We aim to examine the variation in the diagnosis of IBD using survey-administered clinical vignettes to validate international cooperation in research.