DPP4 and type 2 diabetes mellitus: Another safety concern is that the use of DPP-4 inhibitor might be associated with an increased risk of cholangiocarcinoma (hazard ratio (HR) 1.77, 95% CI 1.04–3.01) [36] or inflammatory bowel disease (HR 1.75, 95% CI 1.22–2.49) [37] in adults with T2D.