IL-17 inhibitors effectively treat psoriasis and psoriatic arthritis but may increase the risk of inflammatory bowel disease (IBD). We assessed their association with IBD compared to apremilast. Utilising the TriNetX database, we analysed patients with psoriasis or ankylosing spondylitis initiating IL-17 inhibitors or apremilast. We used propensity score matching and Cox models to estimate IBD risk. Among 13,216 matched patients per group, 142 developed IBD with IL-17 inhibitors versus 60 with apremilast (aHR = 2.50, 95% CI: 1.85-3.39). IL-17 inhibitors increase IBD risk, necessitating careful patient selection and monitoring.