How to Prevent Traveler's Diarrhea: A Dermatologist-Grade Travel Guide

You've booked the trip of a lifetime, and now you're picturing yourself stuck in a hotel bathroom instead of out exploring. Traveler's diarrhea is the most common travel-related illness, so that worry is understandable. The good news: a handful of simple, evidence-based habits can dramatically lower your odds of getting sick.

This guide walks through exactly how to prevent traveler's diarrhea, from what you eat and drink to when a prevention medication actually makes sense. It's general education, not a substitute for advice from your own clinician or a travel-medicine clinic.

What Is Traveler's Diarrhea?

Traveler's diarrhea is loose, frequent stool that develops while traveling, usually after eating or drinking something contaminated. It's the most predictable travel-related illness, with attack rates of roughly 30% to 70% over a typical two-week trip, depending on your destination and the season.

Bacteria cause the large majority of cases, accounting for at least 80% to 90% of them. Enterotoxigenic E. coli (ETEC) is the single most common culprit worldwide, responsible for roughly 30% to 60% of cases. The highest-risk destinations are South Asia, followed by sub-Saharan Africa and South America. Knowing your destination's risk level helps you decide how cautious to be.

How Does It Spread, and What Actually Causes It?

Traveler's diarrhea spreads through contaminated food and water. According to Mayo Clinic, contaminated water is the number one cause, and ice cubes made from that water carry the same pathogens. Raw produce washed in local water, undercooked food, and unpasteurized dairy are other common sources.

Here's a humbling reality: studies show that travelers who carefully follow the classic 'boil it, cook it, peel it, or forget it' rule can still get sick. That's because restaurant hygiene practices and a region's overall sanitation infrastructure are the largest drivers of risk, and those are mostly outside your control. Personal precautions help, but they aren't a guarantee, which is why hand hygiene and smart choices matter so much.

How to Prevent Traveler's Diarrhea With Food and Water

Your most reliable everyday defense is careful food and beverage choices. The CDC's food and water precautions give a clear framework you can follow at every meal.

• Eat food that is cooked and served hot; steam is a good sign.
• Avoid raw or undercooked meat, seafood, and eggs.
• Skip unpasteurized milk and dairy products.
• Eat fruit only if you peel it yourself; avoid pre-cut or pre-washed produce.
• Drink only sealed bottled water or water that has been boiled or properly disinfected.
• Avoid ice, since it is often made from untreated tap water.
• Use bottled or treated water even for brushing your teeth in high-risk areas.

How to Prevent Traveler's Diarrhea With Hand Hygiene

Hand hygiene is one of the most effective and underrated defenses. The CDC recommends washing your hands with soap whenever it's available, especially before eating and after using the bathroom.

When soap and water aren't an option, use a hand sanitizer that contains at least 60% alcohol. Keep a travel-sized bottle in your bag so you always have it before meals, after handling money, and after touching shared surfaces like handrails and door handles.

Do Prevention Medications Work?

For most travelers, careful habits are enough, and routine preventive antibiotics are generally not recommended. But for some higher-risk travelers, medication to prevent traveler's diarrhea can be discussed with a clinician.

The CDC favors non-antibiotic options first. Bismuth subsalicylate is the primary non-antibiotic preventive agent: a 2024 network meta-analysis of 31 studies and 10,879 participants found that taking 2 chewable tablets four times per day reduces the incidence of traveler's diarrhea by approximately 50%. Antibiotic prophylaxis such as rifaximin is reserved for specific high-risk situations, in part because of concerns about antimicrobial resistance.

If you and your clinician decide medication is appropriate, here is roughly how the options compare:

• Bismuth subsalicylate: reduces traveler's diarrhea incidence by about 50%; a non-antibiotic option, but requires frequent dosing.
• Rifaximin: provides protection rates of about 48% to 72% (lower in Asian than Latin American destinations), with side-effect rates similar to placebo; reserved for higher-risk travelers.
• Routine broad-spectrum antibiotics: generally discouraged for prevention due to resistance concerns.

When to See a Doctor

Most cases of traveler's diarrhea are mild and improve on their own. But you should seek medical care, ideally before or during your trip if symptoms are severe, when warning signs appear: high fever, blood in the stool, severe or persistent abdominal pain, signs of dehydration (dizziness, very dark urine, little to no urination), or diarrhea that doesn't improve after a couple of days.

Dehydration is the main danger, especially for young children, older adults, pregnant travelers, and people with chronic illnesses. If you fall into a higher-risk group or are heading to a high-risk region like South Asia, talk with a clinician or travel-medicine clinic before you go. Telehealth tools, including Nolla, can be a convenient way to get a personalized plan and discuss whether prevention medication is right for you.