Travel diarrhea: prevention before the trip, treatment if it happens anyway

You've booked the flights and packed the sunscreen. Few travelers plan for their gut. Traveler's diarrhea is common enough in unfamiliar places that you should expect the possibility, not just fear it. You can't guarantee it skips you, but you can cut your odds well before you leave home. If it does happen anyway, knowing what to do next can turn a miserable week into a rough day or two. If travel itself, not just diarrhea, is a recurring gut challenge for you, our guide to gut health for people who travel for work covers the bigger picture.

Start prevention before you pack

Saccharomyces boulardii is a beneficial yeast, not a bacteria, that some research links to fewer cases of traveler's diarrhea. A large placebo-controlled trial of about 3,000 travelers found a real reduction in diarrhea among people who took it consistently, with the strongest effect among those heading to North Africa and Turkey.¹ Overall evidence on probiotics for preventing traveler's diarrhea is still mixed, so treat this as one reasonable option rather than a sure thing.² If you decide to try it, start three to five days before departure. Your gut needs a little lead time before it meets unfamiliar food and water.

Bismuth subsalicylate, the active ingredient in some over-the-counter stomach remedies, is another option with real evidence behind it. Studies show it cuts the risk of traveler's diarrhea by roughly half when taken on a regular dosing schedule throughout a trip.² It requires dosing several times a day, can turn your tongue and stool black, and isn't right for everyone, so check with your doctor first if you have an aspirin allergy, gout, kidney issues, or take blood thinners.

Having all of this in your bag before you need it means you're not hunting for a pharmacy in an unfamiliar city while you feel awful.

Food and water choices that lower your risk

Stick to bottled or properly treated water, and use it for brushing your teeth too in destinations where the tap water carries risk. Restaurants and food stalls with a steady stream of customers tend to be safer than empty ones, since food that gets cooked and eaten fast doesn't sit around long enough to grow bacteria. Skip unpeeled raw fruits and vegetables, and go easy on ice unless you can confirm it was made from treated water. Heading somewhere high-altitude too? Altitude itself can affect your gut independent of food and water. Research on food and water counseling shows that being careful alone doesn't reliably cut your risk,² so pair these habits with the prevention steps above rather than relying on caution by itself.

The first 24 hours if it happens anyway

Focus on rehydrating right away, replacing lost salts and minerals, not just water. An oral rehydration sachet does this better than water alone, since plain water doesn't replace the salts you're losing along with it. Most mild to moderate cases clear up within a few days if you rest and keep fluids up. Avoid dairy, fatty food, and alcohol until your stomach settles. A hangover recovery calls for skipping those same foods, for similar reasons. All three tend to drag symptoms out longer than they need to.

Anti-diarrheal medication: when it helps

Loperamide can be a reasonable option for a long travel day or a commitment you can't miss. Skip it if you have a fever or blood in your stool. Your body may be fighting an infection that has moved past your gut lining, and slowing everything down with medication can let that infection linger longer than it should.²

Most travel insurance plans include a 24-hour medical assistance line that can point you to reliable local care. Save that number in your phone before you leave, not after you're already feeling sick.

What to do with this

This content is for educational purposes only and is not a substitute for professional medical advice.