Three things do the real work. Azithromycin covers the bugs behind roughly eighty percent of travelers' gut infections, including the strains in South and Southeast Asia where the older drugs stopped working ¹. Oral rehydration salts to the WHO formula pull water through an inflamed gut wall faster than plain water can ². Loperamide slows things down enough to sleep, or board a bus. Together they turn a moderate infection from a four-day event into an evening.

The right antibiotic shortens the average episode by one to two days, and adding loperamide is faster still ¹. Rehydration salts have been on the WHO essential-medicines list since 1978, after they cut childhood-diarrhea mortality by about seventy percent ². In high-risk regions — sub-Saharan Africa, South Asia, parts of Latin America — attack rates over a couple of travel weeks have historically run thirty to seventy percent ³. The benefit is conditional: you only collect it on the trips where something goes wrong.

Build it two to six weeks out — enough lead time for a travel-clinic appointment and prescriptions, tight enough that nothing's expired by departure. A travel-medicine visit (or a telehealth equivalent) matches the antibiotic to your region and handles malaria pills and vaccines in one pass.

Use it by threshold. Mild (annoying, day still doable): hydrate, a loperamide if you must travel, no antibiotic. Moderate (skipping the plan): loperamide plus start the antibiotic. Severe (fever, blood, vomiting, bedbound): antibiotic and salts now, and no loperamide on its own ⁴. If nothing improves by forty-eight hours, find a doctor.