CRP and inflammatory bowel disease: CRP is an acute-phase protein that is synthesized in the liver after stimulation with IL-6.1 It is the most widely used surrogate marker for monitoring the clinical disease activity of IBD.2 However, the existing serum markers represented by CRP are not sensitive enough to identify all patients with endoscopic disease activity because some patients with endoscopically proven intestinal tract inflammation have mild clinical symptoms or normal CRP levels, making it difficult to evaluate disease activity.