AIM: To assess the value of fecal calprotectin as a non-invasive screening biomarker in differential diagnosis of irritable bowel syndrome (IBS) and inflammatory bowl disease (IBD) using ELISA quantitative analysis.METHODS: A total of 92 fresh fecal samples were collected from the patients, including 23 cases of UC, 4 cases of CD, 55 cases of irritable bowel syndrome (IBS) and 20 healthy volun-teers. EK-CAL was used to quantitatively dete rmine the level of fecal calprotection.RESULTS: The level of fecal calprotection was 77.15 ± 160.9 μg/g in healthy volunteers, 46.08 ± 131.97 μg/g in IBS patients, 851.34 ± 522.19 μg/g in IBD patients, respectively. There was no signifi cant difference between IBS patients and healthy volunteers (P 0.05) in levels of fecal calprotection, but there was remarkable difference between the patients with IBS and healthy volunteers. The sensitivity and specif icity of fecal calprotection in differentiating the IBD from IBS was 86.7%, 96.3%, respectively.CONCLUSION: Detection of fecal calprotectin is simple, inexpensive, repeatable and non-invasive. It can be used as a biomarker in differentiating irritable bowel syndrome from inflammatory bowel disease.