TNF and irritable bowel syndrome: CRP is an acute-phase reactant produced by hepatocytes in response to stimulation from inflammatory cytokines such as interleukin-1, interleukin-1β, and tumor necrosis factor-alpha [24], whereas, ESR indicates the migration speed of red blood cells in plasma [25] Meta-analysis aimed to assess the utility of CRP, ESR, FC, and fecal lactoferrin to exclude inflammatory bowel disease in adults with IBS demonstrated that at a CRP level of ≤0.5 or calprotectin level of ≤40 μg/g, there was a ≤1% probability of having IBD.