TABLE 1.

Available tools for assessing the level of disease-associated inflammatory activity.

Tool	Additional notes
Blood inflammatory markers (153, 154)	• Serum CRP and albumin can be used as parallel measures of disease severity/inflammation • CRP can be used as a prognostic marker for the effectiveness of therapy • ESR is a marker for inflammation but can be influenced by factors such as pregnancy, older age and anemia and is not widely used currently
Fecal biomarkers (1–4, 13, 155)	• Fecal calprotectin is a useful biomarker to assess the degree of mucosal inflammation • Fecal calprotectin is correlated with endoscopic inflammatory scores • Fecal calprotectin should be used in the management of patients with IBD
Endoscopy (156)	• “Gold standard” for assessing the response to treatment in patients with UC and CD
Histology (157)	• Endoscopic biopsies or resection specimens
Cross-sectional imaging (39, 158–162)	• MRI and computed tomography have a high sensitivity and specificity for assessing CD activity and can be used to monitor response to treatment • Bowel ultrasonography is increasingly being used in clinical practice       ∙ Good correlation between bowel ultrasound findings and CD activity and location, as well as endoscopic remission       ∙ Accurate method for assessing transmural healing, correlating well with time-consuming and costly MRI       ∙ Convincing support for the use of ultrasonography as a monitoring tool for UC

CD, Crohn’s disease; CRP, C-reactive protein; MRI, magnetic resonance imaging; UC, ulcerative colitis. ESR, erythrocyte sedimentation rate.