Persistent Traveler's Diarrhea

Bradley A. Connor, MD, Brian R. Landzberg, MD

In This Article


This is the first in a new series of columns dedicated to travel medicine. In these times of evolving geopolitical and microbiologic crises, knowledge of issues in travel medicine has become more important than ever. Treating patients in pretravel and post-travel settings requires a knowledge of emerging infections and new diagnostic, preventive, and therapeutic modalities, as well as a return to the venerated principles of a thorough history and physical examination. No subject within travel medicine more clearly demonstrates these points than does persistent traveler's diarrhea (PTD).

Traveler's diarrhea affects 20% to 50% of persons who travel to tropical and semitropical areas, including Latin America, parts of the Caribbean, southern Asia, and Africa, and is the most common ailment encountered by travelers.[1,2] Fortunately, most of these cases are self-limited to a duration of less than 1 week. However, a minority of patients will experience a more protracted course -- an overview of several studies found that between 3% and 10% of travelers may have diarrhea that lasts for more than 2 weeks and that 0.8% to 3% will have symptoms that last for more than a month.[3,4,5,6,7] PTD may be defined as diarrhea that arises in the traveler or recently returned traveler and lasts for more than 3 to 4 weeks.

The usual concern is to rule out a persistent bacterial infection or parasitic infestation. This clearly remains the first task in the evaluation, and we should remain vigilant for emerging pathogens. However, when results of stool studies are negative, the physician needs to broaden his or her differential diagnosis and to apply basic principles of gastroenterology as well as infectious disease. Many patients who have PTD will have cleared the offending pathogen long ago and may present with postinfectious sequelae, be they inflammatory, malabsorptive, or functional. Others may have a chronic noninfectious GI disease that has been unmasked and brought to medical attention by a superimposed enteric infection. One can broadly subdivide the syndrome of PTD into several pathogenetic subsets: persistent infection or infestation, postinfectious processes, and chronic GI illnesses unmasked by an infection ( Table 1 ).