Crohn’s disease and ulcerative colitis are heterogeneous inflammatory bowel diseases, and therapeutic requirements vary among patients. We have a limited capacity to predict disease progression for individual patients, therefore it is important that they are evaluated for the presence of active disease when symptoms are mild or even absent, when patients are more likely to respond to new treatment interventions. It then is important to monitor responses to treatment, to quickly identify those therapies that are ineffective, modify or change therapy, and avoid disease complications. Studies are underway to assess the effects of different monitoring strategies. Because of the heavy burden of severe inflammatory bowel disease on patients’ health and quality of life, and the association between intestinal healing and disease progression in high-risk patients, a treat-to-target strategy (based on tissue healing) is likely to be optimal.