Etiology of Travelers' Diarrhea in Australian Tourists Traveling to Southeast Asia

The study proposed here will determine the frequency and etiology of diarrhea in Australian adult tourists traveling to Southeast Asia, including Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Thailand, Timor-Leste, and Vietnam. The results from this study will inform the feasibility and design of subsequent clinical trials of travelers' diarrhea interventions in this population.

Inclusion Criteria: * Adult aged \> 18 years residing in Australia. * Planned travel for 14 to 28 days starting in the next 30 days to selected countries in Southeast Asia, including Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Thailand, Timor-Leste, and Vietnam. * Willing to participate in the clinical study and available for all planned study activities through approximately 28 days post-travel. * Access to a smartphone and mobile phone services while traveling (either by local SIM card, WiFi, or international roaming service on the individual's home-country mobile phone). Exclusion Criteria: * Unable or unwilling to provide adequate informed consent.