Previous study of Schoepfer et al5 demonstrated the relationship between the Simple Endoscopic Score for Crohn’s disease (SES-CD) and FC, CRP, and CDAI and reported that the overall accuracy for the detection of endoscopically active disease was 87% for calprotectin, 66% for increased CRP, and 40% for CDAI ≥ 150, indicating that FC correlates closest with SES-CD and therefore activity of CD. Here, CRP is linked to glycogen storage disease VI.