Calprotectin is a reliable noninvasive marker for differentiating gastrointestinal inflammation associated with Inflammatory Bowel Disease (IBD) from inflammation that may be associated with Irritable Bowel Syndrome (IBS). Such differentiation is very important because IBD can be life-threatening. Monitoring the levels of fecal calprotectin can play an essential role in determining the effectiveness of clinical interventions, and is a good predictor of IBD remission and relapse. Calprotectin provides clinicians with a valuable tool, not only for differentiating IBD from IBS, but also allowing them to monitor and predict treatment outcomes and enabling better management of IBD flare-ups.