Measuring disease activity in Crohn's disease

In the last few years the management of Crohn's disease (CD) has changed due to the introduction of new therapeutic agents that provide more alternative options in patients with severe diseases, introducing new concepts regarding treatment timing. At the moment, the absence of good predictors of disease outcome and a subclinical marker available to predict relapse during clinical remission are major problems in the management of CD. In recent decades, the evaluation of several variables has been proposed to address this issue, including disease behavior, clinical-endoscopic activity and intestinal damage. In particular, definition of mucosal restitution or healing after therapy has been proposed as a surrogate of efficacy and new goal of the therapy. Regarding this concept, several criticisms have been raised, such as the need to better define the role of mucosal healing in a transmural disease. In order to address this issue, new alternative techniques providing both extraluminal and luminal intestinal damage have been proposed, including ultrasonography, computed tomography and magnetic resonance imaging.