Travellers’ Diarrhea
For business or pleasure, to visit friends and family or explore the world, Canadians love to travel. There were 36,006,662 passenger trips going to or coming from overseas destinations (international excluding the US) in Canada during 2023.1 While travel can be exciting, there are also risks. One of these is travellers’ diarrhea.
The primary cause of travellers’ diarrhea is exposure to pathogens while travelling outside of your home environment. However, you can also develop diarrhea while travelling due to factors such as climate and mental health.
Amazingly, up to 60% of travellers experience diarrhea!2 It usually occurs during the early part of a trip but can arise at any point. Symptoms might not even start until a person has been back home for a few days. Infectious diarrhea typically lasts for only a few days, but can be longer, especially if protozoa are causing the infection. It is also important to note that a single infection does not provide immunity, as you can get multiple bouts of travellers’ diarrhea within a single trip. Diarrhea caused by changes in environment, climate, or mental health status can persist as long as the trigger remains an issue.
Symptoms and Complications
The main symptom of travellers’ diarrhea is, unsurprisingly, diarrhea. This means passing loose stools at least three times per day. However, diarrhea can occur much more frequently and/or be very watery, and it is often accompanied by abdominal cramping and pain as well as the sudden need to have a bowel movement (urgency). Nausea and vomiting are also common symptoms.
In more severe infections, fever, bloody stools, and chills are possible symptoms, and you should seek medical care if you experience any of these.
The main complication of travellers’ diarrhea is dehydration. The gut draws water from the rest of the body to help flush out the infectious pathogen, which forms diarrhea and can quickly dehydrate a person if they are unable to replenish fluids and electrolytes. Those who are especially susceptible to the effects of dehydration, such as infants and young children, seniors, and individuals who have a condition or take a medication that causes them to be immunocompromised, should see a healthcare professional if they experience ongoing diarrhea. In very rare cases, it is possible to die from untreated severe dehydration.
Another complication of travellers’ diarrhea is post-infectious irritable bowel syndrome (PI-IBS). Irritable bowel syndrome is a functional digestive condition defined by abdominal pain and bloating along with constipation and/or diarrhea. There are many potential causes of this condition but, in some cases, travellers’ diarrhea caused by a pathogen can trigger this type of IBS. PI-IBS occurs in roughly 3-17% of those who have had travellers’ diarrhea.3 If you experience ongoing digestive symptoms after travelling abroad, make sure you let your healthcare team know.
Risk Factors
While anyone can get travellers’ diarrhea, some people are at an increased risk of developing the condition and/or having worse outcomes. This includes those who have underlying health conditions, are immunocompromised, or are already living with digestive diseases or disorders, such as inflammatory bowel disease, irritable bowel syndrome, or celiac disease. In addition, infants, young children, pregnant women, and seniors tend to have a higher risk of complications.
Certain medications used to treat gastroesophageal reflux disease (GERD) work by decreasing the amount of stomach acid your body makes, which can be a problem because stomach acid helps destroy pathogens that enter the body via the mouth. If you take histamine-2 receptor antagonists (H2RAs) or proton pump inhibitors (PPIs), make sure you are extra careful about what you eat and drink (see prevention tips below), as you have a weakened line of defense.
The type of trip you take can also influence your risk. Individuals who are backpacking or on a cruise are more likely to have exposure to contaminated food and drinks than those who fly/drive and stay in hotels. People who are staying with friends and family are more likely to develop travellers’ diarrhea than those travelling on business. These differences in risk come down to the types of food and drinks these individuals are exposed to. Those who are backpacking might eat at inexpensive street vendors or drink contaminated water, individuals on cruises could contract a virus or eat at risky buffets, and those who are visiting friends and family eat home-cooked meals that might not be prepared to a high enough standard.
Your travel destination is one of the most important risk factors, as countries with higher incomes tend to have much safer drinking water, whereas lower income regions are higher risk (see below). However, you can still get travellers’ diarrhea in low-risk nations, especially if you are adventuring off-grid and drinking water from streams or rivers. Watch for posted signs about water quality in the region where you are travelling.
Risk Level by Area of Travel4
Low Risk
- Australia and New Zealand
- Canada
- Japan
- Northern and Western Europe
- United States
Moderate Risk
- Caribbean
- Eastern Europe
High Risk
- Africa
- Asia
- Central and South America
- Mexico
- Middle East
Infectious Causes
Typically, exposure to microorganisms through contaminated food and beverages causes travellers’ diarrhea. Common types include bacteria such as Escherichia coli, Campylobacter jejuni, Salmonella, or Shigella and protozoa such as Giardia duodenalis, Entamoeba histolytica, or Cryptosporidium parvum. In areas where there are many people in a contained space, such as cruises or resorts, outbreaks of rotavirus or norovirus can cause digestive sickness.2
It is important to know that contaminated water isn’t only a problem if you drink it directly. Contaminated water includes drinking water, ice used in any beverage, brushing teeth with tap water, and swallowing water while swimming. Foods washed with contaminated water can become infectious if they are uncooked, so salads and sliced fruits are higher risk than cooked foods. Even dishes and utensils washed with contaminated water can cause infection. Raw meat and seafood, as well as food stored at inappropriate temperatures are all options that are more likely to have pathogenic bacteria.
Diarrhea from Overheating
Many people who live in colder climates vacation in warm, tropical countries and are at risk of overheating. This can cause a stress response that increases cortisol production, leading to dehydration and electrolyte imbalance, all of which can contribute to diarrhea.5 Living with obesity, diabetes, or heart disease increases your risk.
Overheating exists on a spectrum, with some forms being mild and easy to treat and others being incredibly dangerous. Heat exhaustion has symptoms such as diarrhea, vomiting, dizziness, weakness, headaches, and muscle cramps and is less serious. Heat stroke is a medical emergency that involves body temperature above 40°C, hot and dry skin, vomiting, diarrhea, low blood pressure, rapid breathing, confusion, hallucinations, and fainting, and can lead to organ failure and death.
To reduce your chance of developing heat exhaustion or heat stroke in warm climates, make sure you stay hydrated, avoid overexertion in the sun, and take breaks in cool locations. If you experience mild heat exhaustion, get out of the heat, have a cool bath, and drink plenty of fluids. If you think you or someone you are with has heat stroke, seek immediate medical help.
Other Causes of Diarrhea When Travelling
Aside from infectious causes and overheating, there are other reasons for someone to get diarrhea while abroad. Travelling can sometimes bring out intense emotions – both negative and positive, which might result in diarrhea. This is especially true for those with underlying anxiety or mood disorders.
In general, a sudden increase in physical activity can lead to diarrhea. If you normally live a sedentary lifestyle but spend all day walking around and sightseeing while on vacation, you might find yourself needing the toilet more often. Changes in diet can have a similar effect if the location you are visiting typically serves food that is higher in fibre, fat, or spices than in your usual diet.
Even lack of sleep from jet lag can affect your normal bowel movements, leading to diarrhea or constipation.
Prevention
If you have an underlying condition (physical or psychological) that increases your risk of infection or diarrhea, make sure you follow your typical management plan and ask your healthcare team for any additional steps to take while travelling.
There are medications that might help prevent travellers’ diarrhea, including rifaximin, fluoroquinolones, and bismuth subsalicylate.6 There is also a vaccine for Cholera and travellers’ diarrhea, but it isn’t very effective. Speak with your physician or a travel clinic for any medication recommendations based on your health status and location of travel.
While travellers’ diarrhea is extremely common, there are steps you can take to reduce your risk.
- do not drink water, or beverages that contain water or ice in high-risk areas (use bottled or treated water for drinking, washing food, and brushing teeth)
- do not eat raw fruits or vegetables, especially those that are pre-chopped, unless they have a thick peel that you remove yourself
- do not eat raw or undercooked oysters, meats, or eggs
- do not eat foods made with unpasteurized dairy
- do not drink a bottled beverage unless you personally remove the cap or watch someone else remove it
- avoid buffets and food sold by street vendors
- research the quality of water where you are going and prepare accordingly (e.g., make sure you have access to bottled water or tools to sterilize water, if applicable)
- wash your hands often, especially before eating; using contaminated water is okay if you also use soap and wash properly; if no running water is available, use hand sanitizer
- avoid getting water in your mouth while showering, bathing, or swimming
- prepare for the climate in your destination: dress for the weather, ensure proper hydration, avoid excessive heat or too much time in direct sunlight
How to Make Water Safe to Drink7,8,9
Note: These methods are for water that might be contaminated with microorganisms. However, there are places where water is unsafe to drink due to contamination with heavy metals, industrial chemicals, radioactive fallout, or other dangerous materials. In these cases, you must drink only bottled water from a reputable source. Always research the water quality in your destination before travelling.
Before treating with the following methods, the water should be clear. If it has sediment, you can filter it through a clean cloth, coffee filter, or a product designed for this purpose. Filters designed to clean water are helpful because they can remove protozoa and larger bacteria. However, they do not make water safe to drink on their own because they do not destroy viruses or smaller bacteria, so they should be used in conjunction with the methods listed below. There are products designed for this purpose, but make sure to follow the manufacturer’s instructions for use.
Boiling
The best, and often simplest, method of treating water is boiling. However, you must bring it to a full boil for at least one minute at lower altitudes, or three minutes if you are more than 1,500 metres above sea level, to destroy microorganisms. Then, keep it covered to prevent further contamination while it cools to a drinkable temperature. This kills most bacteria, viruses, and protozoa.
Chemical Disinfection
There are commercial products available to disinfect water. Always read the instructions carefully and follow them exactly. You can also use household bleach by adding 2 drops from a medicine dropper to each litre of water you are disinfecting. Mix very well and wait for 30 minutes. If there is a slight chlorine smell to the water and it looks clean, it is likely disinfected. If there is no smell and the water is cloudy, repeat the process. Chemical disinfectants are effective at removing bacteria and viruses, but not protozoa.
Ultraviolet (UV) Light
There are UV light wands that you can use to disinfect water. However, these tend to be difficult to use, as they only work on small amounts of water at a time, require the water to be completely clear, take a long time to work, and might be ineffective if their batteries aren’t fully charged. While other methods are preferrable, if you do choose to use UV light, make sure to follow the manufacturer’s instructions very carefully.
Treatment and Management
For cases of travellers’ diarrhea caused by bacteria or protozoa, antibiotics/antiprotozoal medications can help. However, many physicians advise against taking these for milder cases since antibiotic use has risks, such as C. difficile infection.
Other medications, such as bismuth subsalicylate (Pepto-Bismol®) or loperamide (Imodium®) can reduce symptoms in mild cases. Try to avoid these for the first few days of diarrhea in cases caused by bacteria/protozoa, as it is important for your body to evacuate these pathogens. If you take medications to treat a chronic condition, then speak with your physician before travelling about how diarrhea and/or vomiting might affect your medication’s efficacy and whether you should modify the way you take them.
The primary goal when treating travellers’ diarrhea is preventing severe dehydration. Focusing on getting enough fluids is important for all sources of diarrhea, as dehydration is a serious risk. Make sure that all water you consume is safe to drink (bottled, boiled, or disinfected, depending on what is recommended in the area of travel).
Rehydration solutions are important for maintaining proper electrolyte balance, especially if diarrhea is moderate or severe. Younger children and clinically vulnerable individuals should consume these even during mild cases. Healthy adults and older children don’t necessarily need them if diarrhea is mild, but they can still be helpful.
You are especially prone to dehydration if you are travelling to a location with high temperatures, are very active, or are in any other situation that increases how much you sweat. Make sure you are staying well hydrated so that if you do develop diarrhea, you have a good baseline of hydration.
While sick, consume small amounts of foods that are low in fat and fibre, and easy on the digestive system, such as simple carbs (e.g., white rice, pasta, dry toast, crackers, applesauce, bananas) or easier to digest proteins (e.g., eggs, chicken, fish). Avoid drinking anything with caffeine (e.g., coffee, tea, cola, energy drinks) or alcohol.
Outlook
Most cases of travellers’ diarrhea resolve within a few days to a few weeks, and it is best to focus on rest and hydration. However, severe cases can occur, especially in young children, seniors, and those with underlying health conditions. These individuals might experience severe dehydration that requires medical attention, such as hospitalization. In addition, there is a risk for post-infectious irritable bowel syndrome, which can last for many years and cause a significant change in an individual’s quality of life.
