Fecal calprotectin and lactoferrin levels are elevated and stable in patients with intestinal inflammation. Compared with traditional inflammation markers such as fecal white blood cell (WBC) count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and procalcitonin (PCT), the results of fecal calprotectin and lactoferrin testing are independent of WBC morphology. These markers are sensitive to inflammation in both the small and large intestines, including localized mild infections and chronic inflammation. Therefore, fecal calprotectin and lactoferrin testing provides higher sensitivity and specificity for intestinal inflammatory diseases.

Inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and intestinal tumors are the most common outpatient intestinal disorders. IBD and intestinal tumors are organic lesions characterized by inflammatory infiltration of intestinal tissue, whereas IBS is a functional disorder without tissue inflammation. As a result, fecal calprotectin and lactoferrin testing can effectively distinguish IBD from IBS and assist in the early detection of intestinal tumors. Combined testing of fecal calprotectin and lactoferrin further enhances the detection rate and accuracy of diagnosing intestinal inflammatory diseases.