Treat to target or 'treat to clear' in inflammatory bowel diseases: one step further?

INTRODUCTION: Inflammatory bowel diseases (IBD) are chronic and progressive diseases. Long-term complications are demolitive surgery and colon-rectal cancer. A 'treat to target' strategy, in which the treatment aims to achieve objective outcomes, has already been introduced in the management of chronic conditions as rheumatic diseases. This approach is emerging as suitable for ulcerative colitis and Crohn's disease. Targets are predefined therapeutic goals demonstrated to prevent end-organ dysfunction. An optimization or switch of therapy is considered depending on the target's achievement, with regular monitoring. AREAS COVERED: According to the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) indications, mucosal healing and clinical remission are the main targets in IBDs. Histological remission is increasingly being considered as a novel target and has given rise to the new concept of 'disease clearance' which includes clinical, endoscopic and microscopic remission. We aim to review current evidence on the treat-to-target strategy in comparison to a stricter treat-to-clear in the IBD field. EXPERT OPINION: Prospective studies on treat-to-target algorithm are sparse; a treat-to-clear approach is desirable but far from adoption in the daily practice and clinical trials. The ultimate goals of a treat-to-clear strategy differ in UC and in CD, including histological healing and transmural healing, respectively.