Management of the returning traveler with diarrhea

Traveler's diarrhea (TD) strikes 20-60% of travelers visiting developing countries. It occurs shortly after the return and can be distinguished into two categories: acute and persistent TD. Acute TD, mostly caused by bacterial and viral pathogens, is usually mild and self-limited, and deserves empirical symptomatic and/or antibiotic therapy in selected cases. Fluoroquinolones are progressively superseded in this indication by azithromycin, a well tolerated macrolide active against most bacteria responsible for TD, including the quinolone-resistant species of Campylobacter jejuni that are now pervasive, especially in Southeast Asia and India. Persistent TD in the returning traveler is much rarer than its acute counterpart and may be associated with three types of causes. Persistent infections, among which Giardia and possibly Entamoeba predominate, account for a significant proportion of cases. Postinfectious processes represent a second cause and comprise temporary lactose malabsorption and postinfectious irritable bowel syndrome, now considered a major cause of persistent TD. Finally, apparently unrelated chronic diseases causing diarrhea are occasionally unmasked by TD and represent a third type of persistent TD, among which the well established case of incident inflammatory bowel disease poses intriguing pathogenesis questions. This review discusses recent advances in the field and provides practical recommendations for the management of TD in adult, immunocompetent returning travelers.