What Is Traveler’s Diarrhea? A Dietitian Explains Everything

What we're going to learn about traveler's diarrhea

So you just got back from an epic around-the-world adventure and your stomach’s really unhappy. Or maybe you’re still overseas and experiencing an unpleasant bout of the runs.

• Did you pick up traveler’s diarrhea from the scorpions and insects you bravely tried at a street food stall?
• Or was it because the vendor who sold you the scorpions didn’t wash their hands properly after going #2?
• Or maybe you picked up traveler’s diarrhea NOT because of exotic street food; but simply because you brushed your teeth with tap water, which had bacteria your system wasn’t used to?

Either way, you’re in luck, because in this video we’re going to cover:

1. The underlying root causes of traveler’s diarrhea, so you know what to look out for
2. Plus how long it typically lasts
3. Just as importantly, we’ll look at the underlying risk factors, so you know when to take extra care
4. And I’ll even answer your most popular questions like; Is traveler’s diarrhea contagious?

How common is traveler's diarrhea?

We wrote this article because it turns out traveler’s diarrhea is the most common travel-related illness.

In fact, according to a 2019 clinical review, between 10 and 40% of people who travel will develop diarrhea! Crazy right?!

Meanwhile, other sources such as the Cleveland Clinic say the true number could be even higher.  Stating that shockingly 30 to 70% of travelers may bring home this unwanted souvenir.

So before we explore the root causes of traveler’s diarrhea let’s define exactly what it is first, so you know if you really have it.

And just before we continue, it’s worth mentioning that as always, this is not medical advice. But rather for information purposes only. And like with all gut health topics, please be sure to consult with your healthcare professional to work out what is best for you.

What is traveler's diarrhea? 

So the definition of Traveler’s Diarrhea, according to the 2019 clinical review we looked at before, is:

1. Having at least 3 unformed stools every day
2. Plus at least one additional symptom such as abdominal cramps, vomiting or fever
3. And of course these problems develop while you’re abroad or within 10 days of returning from a developing country.

And in case you’re lucky enough to have no clue what an unformed stool looks like, according to the Bristol stool chart, it would be any stool that looks like types 5, 6 and 7.

What causes traveler's diarrhea?

So usually traveler's diarrhea comes from consuming water or food that’s contaminated with fecal matter. But it can also be caused by other things, like eating under cooked food. And there’s several different ways you can get traveler’s diarrhea.

8 Common Causes of Traveler’s Diarrhea

Poorly sanitized tap water Ice cubes Drinking water Brushing teeth Food prep Dishes/utensils

Unwashed hands in food prep

Poorly washed fruit & vegetables

Touching contaminated surface

Under cooked meat

Unrefrigerated food

Contaminated surfaces

Different microbes

Our quick list above summarizes the main ways. And as you can see they all revolve around things you drink, eat or touch while traveling.

And the reason these things may make you sick, is because they contain bacteria, viruses or parasites. And when they enter your body they can cause traveler’s diarrhea.

Ok, so now that you know what some of the root causes of traveler’s diarrhea are, let’s find out:

How long does traveler's diarrhea last?

Well, it depends on what caused your diarrhea - was it harmful bacteria, a virus or perhaps even a parasite? And here’s the thing; if you have it, let’s hope it’s either a bacterial or viral infection.

That’s because traveler’s diarrhea caused by bacteria and viruses lasts the shortest amount of time. In fact, according to the CDC

• Traveler's diarrhea caused by bacterial infection usually lasts 3 to 7 days
• While traveler's diarrhea causes by viral infection generally lasts just 2 to 3 days

Now as for diarrhea caused by parasitic infections, according to research published in the journal, Australian Family Physician there’s good news and bad news.

• The bad news is that parasites, like protozoans, can cause diarrhea that may last for 14 days or longer.
• But the good news is that only 1–3% of travelers experience this type of diarrhea.

Now then, let’s next take a look at who is most susceptible to traveler’s diarrhea.

Risk factors for traveler's diarrhea

If you just want the cliff notes, here is a quick list highlighting the 6 main risk factors for developing traveler's diarrhea.

6 Main Risk Factors

Travel from developed to → developing country

Travel to → hot & humid country

Low stomach acid, e.g. antacids, PPIs etc

Not enough good bacteria, e.g. antibiotics

Preexisting GI issues, e.g. IBS

Weakened immune system, e.g. older age

Now let's go through them one by one, so you can understand a bit more how they increase your chances of developing diarrhea.

1. So to start with you’re more likely to get traveler’s diarrhea if you currently live in a developed country and then visit a nation with a developing economy. That’s because there is a higher likelihood of microbes like bacteria being present in the food, tap water and even on surfaces AND your system is likely not used to them
2. Moreover, if the developing nation you’re visiting happens to have a hot & humid climate, that also puts you at a higher risk. And that’s because harmful bacteria are more likely to grow in these conditions. So you may want to keep that in mind the next time you’re thinking about going full Survivor in the tropics.
3. Now the next risk factor for traveler’s diarrhea is having low stomach acid. And that’s because if you don’t have enough stomach acid then bacteria and viruses have a better chance of surviving and moving through your intestinal tract. So if you find yourself traveling and frequently reaching for the antacids for example (which neutralize stomach acid) this can put you at higher risk.
4. Another factor that may increase your chances of getting traveler’s diarrhea is gut dysbiosis. And that simply means that you don’t have enough good bacteria in your gut, which can fight off the bad bacteria.
5. And real quick, a couple other risk factors we should mention are having pre-existing GI issues such as IBS or Ulcerative colitis.  As well as being Immunocompromised.

So now, let’s find out…

Is traveler's diarrhea contagious?

And if you have it, should you be sleeping in a different bed than your partner or even a different room?

Well, the answer is traveler's diarrhea might be contagious, but only under certain circumstances.  In other words, yes and no.

You see, traveler’s diarrhea itself is not easily contagious. In other words, if you have it and breathe on your partner, your partner probably won’t catch it. However, the bacteria, viruses and parasites that cause traveler’s diarrhea can be contagious and can be passed onto others through your fecal matter or even vomit.

So make sure to wash your hands really well after you use the bathroom. And also make sure to disinfect surfaces like toilets extra diligently.

Ok…so next we’re going to take a look at…

Which countries is traveler's diarrhea most likely to occur?

And simply put…you’re more likely to get it in any country that does not have reliable sanitation and water-purification systems.

And according to this 2005 paper in the journal of Clinical Infectious Diseases, the areas of the world where this is most likely includes Central and South America, as well as Africa, the Middle East, South Asia and Southeast Asia. And interestingly, also some risk - albeit much lower - in parts of Central and Eastern Europe, which are shown in light grey color.

In other words, the only places with low risk of traveler’s diarrhea are North America, North Western Europe, as well as Australia and New Zealand.

With that said, keep in mind that infections which cause traveler’s diarrhea can also be picked up at home. Although the risk is much lower of course.

So speaking of which, it’s time for a quick pop quiz:

• Which type of infection do you think is most likely to cause traveler’s diarrhea? Is it bacterial, viral or parasitic? The answer is coming up next…

Bacterial vs Virus vs Parasitic Traveler's Diarrhea - which is most common?

So to find out which type of infection is most likely to cause traveler’s diarrhea, we’ll once again turn to the 2019 clinical review from earlier. And according to that study, up to 90% of travelers' diarrhea is caused by harmful bacteria. So if you answered bacteria, you get a gold star!

As for viruses, they may be responsible for up to 10% of cases of travelers’ diarrhea.

And when it comes to parasites, a research review in the journal Clinical Infectious Diseases, says that "contrary to popular belief only a small percentage of cases of acute traveler's diarrhea are due to parasites". 

Now if you want to stick around for the last section, we’ll find out what the most common types of bacteria, viruses and parasites are that can cause traveler’s diarrhea and ruin your vacation.

But in case you’re wondering what to do if you currently have traveler’s diarrhea, we made another guide for that, which you can find here.

2 main types of bacteria that cause traveler's diarrhea

To be honest, things are going to get a little geeky here as we dive into the science. But don’t worry, because we’ll summarize it all with a table, so you can easily see the answer.

So the most common bacteria that can cause travelers diarrhea is Enterotoxigenic E. coli. Also known as ETEC, this bacteria is - wait for it - the most common pathogen on Earth.  It accounts for up to 60% of all traveler’s diarrhea cases.

Another common bacteria that may cause traveler’s diarrhea is Campylobacter. And you’re more likely to pick up this type of infection by eating undercooked meat.

Now let’s move on and quickly talk about viral infections that can cause traveler’s diarrhea. And don’t worry, as I’ll show you the table summarizing all of these in just a minute.

2 most common viruses that cause traveler’s diarrhea

So according to this 2019 clinical review, out of all viruses that cause traveler’s diarrhea in adults, Norovirus is the most common. In fact, according to the journal, Tropical Diseases, Travel Medicine and Vaccines - yes there really is a journal called that - norovirus causes traveler’s diarrhea anywhere from 10% to 65% of the time.

And you might have heard of this little virus in the past as it has caused many outbreaks on cruise ships.

But if you’re traveling with little ones, according to research in Clinical Infectious Diseases which we looked at earlier, Rotavirus is more likely to strike kids. In fact, rotavirus is the leading cause of severe, dehydrating diarrhea in children worldwide.

And quickly moving on…

2 most common parasitic infections that cause traveler’s diarrhea

As we mentioned, parasites account for the smallest percentage of traveler’s diarrhea cases. But if your diarrhea lasts for two weeks or more then you most likely have a parasitic infection.

And two of the most common parasites that you can pick up while traveling are Giardia lamblia and Cryptosporidium.

Wow, scientists really love giving poor ol’ parasites the most complicated names!

Different causes compared	Bacterial Infections	Viral Infections	Parasitic Infections
Duration of Symptoms	3-7 days	1-3 days	Typically more than 2 weeks
Prevalence	Up to 90% of TD	Up to 10% of TD	0-12% of TD
Examples	Enterotoxigenic E. coli (ETEC) (a type of E. coli) Most common bacterial cause of TD  Causes 30-60% of TD	Norovirus  Most common viral cause of TD  Common on cruise ships	Giardia lamblia Most common parasitic cause of TD
	Campylobacter Main bacterial infection caused by eating undercooked food	Rotavirus  Lead cause of severe diarrhea in children	Cryptosporidium 2nd most common parasite that causes TD

And here’s our summary table showing you how bacterial, viral and parasitic infections compare to each other. And as you can see:

• You’re most likely to experience bacterial infections, usually from e coli
• And the good news is they usually don’t last too long.
• Although, let’s be honest - even 3 days stuck to the porcelain throne can feel like you're Andy Dufraine in Shawshank Redemption!

And so now the question becomes: what do you do if you currently have traveler’s diarrhea?

Traveler's diarrhea treatment

Well to find out how to best overcome traveler’s diarrhea, check out the dedicated article we made for traveler's diarrhea treatment.

You’ll learn about everything from medications to OTCs and even special supplements that can help.

So now we want to hear from you, if you’ve ever had traveler’s diarrhea what do you think caused it? Let everyone know by leaving a comment below.