Both UC and CD are chronic inflammatory diseases with a lifelong and remitting course. While we have learned a lot about the predisposing factors, clinical symptoms, pathways, pathology, and genetics, the exact cause remains unknown. It leads to the situation, when having a seemingly rich armamentarium, we do not have an effective and definite treatment. These diseases remain highly debilitating, and if with the current state of medicine in industrialized countries, are no more fatal, their negative impact on the overall quality of life and economy remains substantial. Clinical trials aimed at discovery of novel therapeutic options are increasing in number annually but in parallel are becoming more complex and challenging.