BACKGROUND: Rosacea is a chronic inflammatory skin disease. Recent studies have indicated its impacts on systemic health beyond dermatological symptoms. The gut-skin axis theory, which explores the interaction between gastrointestinal and skin health, may explain the influence of rosacea on gastrointestinal disorders. This study investigates the potential link between rosacea and the risk of developing irritable bowel syndrome (IBS) using the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC). METHODS: Data for this retrospective cohort study were sourced from 746,060 individuals in the NHIS-NSC database, classified according to the Korean Standard Classification of Diseases (KCD) version 6, based on the International Classification of Diseases, 10th Revision. The drugs were also identified by their GNL code in Korea. We focused on individuals diagnosed with rosacea and their subsequent development of IBS. This study was conducted with 1,087 patients diagnosed with Rosacea between 2002 and 2013 in NHIS-NSC. A total of 4,348 controls were matched at 1:4 based on sex, age, and index data. Adjustments were made for potential confounders such as age, sex, and comorbidities through multivariate Cox proportional hazard models, to assess the risk of IBS among patients with rosacea compared to those without it. RESULTS: Our findings show that individuals with rosacea have a significantly higher incidence of IBS than those without rosacea. After adjusting for multiple potential confounders, the association remained significant, with rosacea patients showing a 21% increased risk of developing IBS compared to controls. The study also noted that the incidence of IBS increased as rosacea became chronic. CONCLUSION: The findings support the hypothesis that rosacea may be associated with an increased risk of IBS, potentially mediated by systemic inflammatory pathways and neurological interactions as suggested by the gut-skin axis. This indicates that gastrointestinal symptoms and diseases should be considered when managing rosacea patients. Further studies are needed to explore the underlying mechanisms of this association and to confirm these findings in other populations.