Calprotectin is a protein found in the cytosol of neutrophi les. Fecal calprotectin is a marker for inflammation in the mucosa of the digestive tract. Abdominal complaints are often nonspecific and can be similar to those of functional and organic diseases Fecal calprotectin helps to distinguish chronic inf lammatory bowel disease ( IBD) from irritable bowel syndrome (IBS). Fecal calprotectin is a simple noninvasive method for differential diagnosis. It is included in the guidelines for IBD and IBS in Europe and it helps to diagnose inflammatory bowel diseases in the early stage. Tests for fecal calprotectin are performed in laboratories using the chromatographic and ELISA methods. Fecal calprotectin tests have >80% sensitivity and specificity for detection of mucosal inflammation in the digestive tract. The use of fecal calprotectin increases the post-test probability of IBD from the pre-test 32% to 91% while normal test result reduces the post-test probability to 3%. Although the fecal calprotectin test is not suitable for screening the risk of colorectal cancer in population, it remains a diagnostic tool for patients with abdominal complaints. Future trends include studies of fecal calprotectin to analyse its diagnostic efficiency and the cost efficacy of fecal calprotectin testing in primary health care.