IAMAT |International Association of Medical Assistance to Travellers| IAMAT |International Association of Medical Assistance to Travellers|
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How to prevent travellers' diarrhea

Don’t get stuck inside during your trip. Travellers’ diarrhea – one of the most common travel-related illnesses – can have a real impact on your health and your travel plans.

What is travellers’ diarrhea?

Travellers’ diarrhea (TD) encompasses gastrointestinal infections caused by ingesting harmful bacteria (strains of Escherichia coli, Salmonella, Shigella, and Campylobacter), viruses (norovirus, rotavirus), protozoa (Giardia, Cryptosporidium) and toxins found in unsafe food and water. These pathogens are found worldwide and are typically transmitted from person to person via the fecal-oral route – an infected person who does not practice good hand or body hygiene passes on the infection to another person, often when handling food and water. Travellers’ diarrhea is a self-limiting infection which usually goes away without treatment.

How can I prevent travellers’ diarrhea?

Your risk of developing travellers’ diarrhea depends on the risks you take eating and drinking, your destination, and the duration of your trip.

Like the rest of our body, our gastrointestinal system needs time to adjust to a new environment. Diverse ways of preparing, cooking, and serving foods, as well as different water quality impact the delicate balance of your gut.

It’s also good to keep in mind that it’s not necessarily what you eat, but where. When we’re travelling, we are less likely to be cooking and handling our own food. Not knowing where it came from, how it was processed, and if the handler(s) followed proper hygiene increases the risk of food poisoning from bacteria, viruses, parasites, or toxins.

Your destination also has a significant impact on your risk. The risk of food-or water-borne infections is highest in countries where hygiene and sanitation are challenging to maintain and food handling practices are not strictly enforced.

Food and water basics

Following food and water precautions can help reduce your risk. Where possible, opt for foods that are served hot and have been well-cooked. Avoid undercooked meat and fish, and fruits and vegetables that have not been washed with treated water. If you are unsure, use the rule: Boil it, Cook it, Peel it, or Forget it!

If the tap water at your destination is not safe, drink boiled or filtered water and use a reusable container to store your water. Try to avoid using single-use plastic water bottles as much as possible, as they are a significant contributor to environmental pollution and rarely recycled. If you do use bottled water, make sure it comes from a reliable source and check that the cap is sealed and has not been tampered with.

See food and water safety for more information.

Hygiene practices

It might be surprising, but practicing good hand hygiene is actually proven to be the most effective method of preventing Travellers’ diarrhea. Carefully wash your hands with soap and water where available. If handwashing is not possible, use an alcohol-based hand sanitizer (with at least 60% alcohol). You can learn more about hand hygiene here.

Preventive medications, supplements, and antibiotics

You should always consult your doctor before taking any medication, supplement, or antibiotic to prevent TD. These products may not be recommended for you and in some cases, their effectiveness is not proven.

Due to growing antibiotic resistance around the world, antibiotics are not recommended as a form of TD prevention. In certain situations, antibiotics may be prescribed as a prevention method for high-risk travellers, such as those with a pre-existing immunosuppressive condition or travellers on short-term work assignments in high risk areas. Antibiotics should only be used as prescribed by a healthcare practitioner – they may be prescribed to reduce the duration of diarrhea caused by bacterial pathogens.

Products containing bismuth subsalicylate (e.g. Pepto-Bismol) can relieve symptoms of heartburn, diarrhea, and indigestion. When used every day as a preventive measure, it may reduce the risk of TD. However, side effects include constipation, nausea, black tongue and stools, and ringing in the ears. Products containing bismuth subsalicylate are not safe for pregnant women and children under 12.

Other products marketed to prevent TD, such as supplements, should be used cautiously. Supplements such as bovine colostrum and pre- and probiotics containing lactobacillus are not sufficiently proven to effectively reduce the risk of TD.


Prophylactic vaccines, such as Dukoral, are also heavily marketed to travellers as a form of TD prevention. Dukoral is an oral vaccine available in Canada and many other countries (excluding the USA) for protection against Cholera and TD.

Dukoral has shown to be about 60% effective at preventing TD caused by Enterotoxigenic Escherichia coli (ETEC), which causes 25-50% of TD cases. It does not protect against other pathogens that cause TD. As a result, it is not recommended for travellers for the prevention of TD and should only be considered when travelling to areas with active Cholera outbreaks.

How can I manage travellers’ diarrhea?

Since travellers’ diarrhea is so common, it’s important to know what to do if you get sick.

Diarrhea is typically categorized as mild, moderate, or severe depending on the symptoms. The following chart provides suggested management strategies for the tree levels of severity:

Type Symptoms Management
Mild Few unformed stools.
Generally tolerable.
Does not interfere with daily activities.
Increase fluid intake and use oral rehydration solution.
Anti-motility agents or bismuth subsalicylate may be used.
Antibiotic is not recommended.
Moderate Loose or liquid stools; cramps or nausea may also occur.
Becomes distressing and interferes with daily activities.
No blood in the stool.
Increase fluid intake and use oral rehydration solution.
Anti-motility agent or bismuth subsalicylate may be used.
An antibiotic is not encouraged but may be used.
Severe Loose or liquid stools that become debilitating.
Cramps, nausea, chills, severe thirst, or inability to keep liquids down.
Prevents all planned activities.
Blood in the stool.
Increase fluid intake.
Use an antibiotic.
Seek medical attention if symptoms do not improve or if blood in stool is present.

(Chart adapted from The Journal of Travel Medicine’s published guidelines)

As outlined in the chart, there are a few key methods that can help you manage TD:

Increasing fluid intake and oral rehydration solution (ORS)

When managing TD, your primary goal is to prevent dehydration. At the first signs of diarrhea, you should start increasing your fluid intake by drinking treated water with an oral rehydration solution (ORS). ORS is a mixture of salt and sugar designed to replenish electrolytes and be rapidly absorbed by your intestines. You can get ORS packets from your pharmacy or you can make your own: Mix 6 teaspoons of sugar with 1 teaspoon of salt in one litre (0.26 gallon) of treated water. Avoid diuretic liquids like coffee and alcohol, which increase water loss.

Anti-motility agents and Bismuth subsalicylate

These products are useful when mild to moderate diarrhea occurs. Anti-motility agents such as loperamide (e.g. Imodium) and bismuth subsalicylate-containing products (e.g. Pepto-Bismol) are drugs that alleviate the symptoms of diarrhea. However, they do have side effects and you should talk to your doctor about whether they are right for you.


Antibiotics can be used if you have moderate to severe diarrhea and when the risk of diarrhea-related complications is high. Travellers to high risk destinations may consider packing emergency antibiotics for use in case TD becomes debilitating and prevents all planned activities.

Before you depart, make an appointment with your doctor or travel health specialist to discuss the use of antibiotics. Make sure you know how to identify the severity of Travellers’ diarrhea and if needed, when antibiotics should be used. Depending on your destination, some antibiotics may not be recommended due to the presence of antibiotic resistance. For example, in Southeast Asia a common cause of TD is infection with Campylobacter spp.. However, the bacteria is now resistant to antibiotics, particularly fluoroquinolone antibiotics like ciprofloxacin, and is gaining resistance to other commonly prescribed antibiotics like azithromycin.

When to seek medical care

You should always seek medical attention if blood is present in stool. You should also get medical attention if severe symptoms such as intense cramps, fever, chills, or dehydration persists and do not improve with treatment.



Last reviewed and updated: December 11, 2020.

Travel Health Journal