OBJECTIVE: Lactoferrin as a glucoprotein that can reflect the activity of neutrophil leukocytes is a specific and sensitive indicator in the evaluation of intestinal inflammation. The aim of this study was to evaluate the relationship between fecal lactoferrin and intestinal inflammation by quantitative analysis and the effect of fecal lactoferrin in measuring the activity of inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn's disease (CD). MATERIAL AND METHODS: A total of 177 fresh stool samples were collected from 42 active UC, 17 inactive UC, 13 active CD, 5 inactive CD, 41 infectious bowel disease, 25 irritable bowel syndrome (IBS) and 34 healthy volunteers. IBD-SCAN was used quantitatively to measure the level of fecal lactoferrin. A modified Harvey-Bradshaw Active Index was used to evaluate the activity of IBD. RESULTS: Fecal lactoferrin was 3.15+/-1.60 microg/g in healthy volunteers, 2.54+/-1.49 microg/g in IBS, 83.3+/-29.9 microg/g in infectious bowel disease, 1126.29+/-431.21 microg/g in active UC, 1035.25+/-456.59 microg/g in active CD, 96.58+/-82.46 microg/g in inactive UC and 133.52+/-88.89 microg/g in inactive CD. Fecal lactoferrin was significantly higher in active IBD than in inactive IBD, IBS and infectious bowel disease. The sensitivity and specificity of fecal lactoferrin were 92% and 88%, respectively, for UC, and 92% and 80%, respectively, for CD. CONCLUSIONS: Fecal lactoferrin is a sensitive and specific marker in measuring the activity of IBD. It provides us with a valid method in discriminating between inflammatory and non-inflammatory bowel disease. In addition, an elevated fecal lactoferrin level can lead us to exclude IBS in clinical practice.