Fecal Calprotectin

Calprotectin is a protein produced by neutrophils, the white blood cells responsible for defending the body against “attacks.” When inflammation occurs in the digestive tract, neutrophils secrete large amounts of calprotectin, which ends up in the stool.

Calprotectin levels above 250 micrograms per grams (ug/g) of stool indicate that an inflammatory process is occurring in the digestive tract (Crohn’s disease, ulcerative colitis, etc.) but they do not specify its location or cause. The higher the calprotectin levels, the more severe the inflammation. High calprotectin levels can also signal a bacterial or parasitic intestinal infection or cancer. High calprotectin levels must be confirmed by colonoscopy to determine the cause of inflammation.

Calprotectin levels below 60 ug/g indicate that the intestinal symptoms are probably due to a more benign bowel condition such as irritable bowel syndrome or a viral infection, thus avoiding the need for colonoscopy in most cases.