Increasing evidences support the use of this biomarker for diagnosis, follow-up and evaluation of response to therapy of several pediatric gastrointestinal diseases, ranging from IBD to cow's milk protein allergy, infectious diarrhea, necrotizing enterocolitis, colorectal cancer, colonic polyps, a non-steroidal antiinflammatory drug induced enteropathy, cystic fibrosis, juvenile idiopathic arthritis, and even untreated celiac disease.