Monitoring Inflammatory Bowel Disease Activity: When, How, and Why

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, are disorders caused by inflammation in the gastrointestinal tract leading to a wide variety of symptoms. The presence of symptoms may not always correlate with active intestinal inflammation, and the lack of symptoms does not always indicate control of inflammation. Owing to the variable correlation between clinical symptoms and active intestinal inflammation, the targets for IBD management have been updated to include objective measures of inflammation to complement clinical end points. In addition to clinical remission, these targets include improvements in biochemical markers and endoscopic measures to objectively measure and monitor disease remission. In this review, we will discuss the different strategies for assessing disease activity and the timing of evaluation for each treatment target for outpatient IBD care. We will also highlight the role of radiographic assessment with a focus on intestinal ultrasound for monitoring these treatment end points.