Diarrhea is a common complaint in primary care offices. It affects the patient's quality of life and increases health care resource utilization. Although most cases of diarrhea are acute and self-limiting, there are multiple causes that can lead to serious morbidity and mortality. Likewise, chronic diarrhea can be a sign of a more serious condition and requires thoughtful evaluation. Ultimately, primary care physicians must take an evidence-based and comprehensive approach to diarrhea to appropriately apply health care resources in the interest of patient care.