Two fecal-derived markers of intestinal inflammation (i.e., fecal lactoferrin and fecal calprotectin) are both diagnostically useful and perhaps superior to serologic tests (e.g., the erythrocyte sedimentation rate and CRP) based on their diagnostic accuracy in discriminating IBD from irritable bowel syndrome with diarrhea [4,25]. Here, LTF is linked to irritable bowel syndrome.