Faecal calprotectin, conversely, indexes neutrophil infiltration into gastro-intestinal (GI) mucosal tissue and is the noninvasive gold standard for indexing inflammation of the gastrointestinal mucosa in IBD, reflecting mucosal inflammation in Crohn’s Disease (CD) more accurately than C-reactive protein or clinical scores such as the Crohn’s Disease Activity Index (CDAI) [19, 20]. Here, CRP is linked to Crohn disease.