IBS is a common disorder affecting 10% to 15% of the adult population. IBS-D can be diagnosed using symptom-based criteria, a detailed physical exam, and select tests to exclude organic diseases. In this activity, clinicians will learn screening and detection methods for IBS-D, including ROME IV criteria, alarm features, and select tests such as complete blood count, C-reactive protein /stool calprotectin, tissue transglutaminase (IgA and IgG), stool analysis, and assessment for bile acid malabsorption.