Diarrhea is the most common gastrointestinal symptom in people with human immunodeficiency virus infections. Diarrhea can appear to be a consequence of infection by an opportunistic germ or the side effect of antiretroviral treatment. It can be acute or chronic, but the latter leads to greater morbidity and alteration in patients’ quality of life. Stages of the diagnostic approach range from taking a complete clinical history, to microbiological, endoscopic and imaging studies. Finally, if infectious or organic causes have been ruled out (idiopathic enteropathy), management provided to the patient should seek symptomatic relief and optimization of adherence to antiretroviral treatment.