What it is
It is the most predictable travel-related illness: according to the CDC, 30% to 70% of travelers get it over a two-week period, depending on the destination and season. Most cases are caused by bacteria; viruses or parasites can also cause it.
It causes frequent loose or watery stools and may come with cramps, nausea or fever.
How to prevent it
- Wash your hands with soap and water before eating and after using the bathroom. If they are not available, use hand sanitizer with at least 60% alcohol.
- Drink only beverages from sealed containers, or boiled or purified water.
- Avoid ice unless you are sure it was made with safe water.
- Choose foods that are fully cooked and served hot.
- Avoid salads, raw vegetables, raw or undercooked meat, fish, shellfish and eggs, and unpasteurized dairy and juices.
- Choose fruit you can peel yourself after rinsing it with safe water.
- Be careful with food and drinks from street stalls.
- Use bottled or purified water to brush your teeth as well.
These measures lower the risk, but they do not eliminate it.
How to rehydrate
Replacing fluids is key to treatment. If the diarrhea is mild, drinking more fluids than usual is enough. If stools are frequent and abundant, use oral rehydration solution, sold in pharmacies, and prepare it with safe water following the package instructions.
Avoid soda and very sugary drinks, because if drunk in large amounts they can make diarrhea worse.
Medicines: always with a medical assessment
Most mild cases do not need antibiotics. Antibiotics require a prescription and an assessment that considers how severe the symptoms are and whether there is fever or blood in the stool, because they also have side effects.
Medicines that slow down bowel movements should not be used alone if there is fever or blood in the stool. Check with a doctor before taking any medicine, especially if you are pregnant, take other medicines or have a chronic condition.
When to see a doctor
See a doctor if you have any of these signs:
- Blood in the stool.
- High fever (over 38.9 °C / 102 °F).
- Signs of mild to moderate dehydration: intense thirst, dry mouth, passing less urine than usual, dizziness when standing up.
- Vomiting that makes it hard to drink.
- Diarrhea that does not improve after a few days.
- Pregnancy, older age or a chronic condition.
Frequently asked questions
Can I drink tap water?
It is better not to. To drink and brush your teeth, use bottled, boiled or purified water, and avoid ice if you do not know what water it was made with.
Do I need antibiotics for traveler's diarrhea?
In most mild cases, no. Antibiotics require a prescription and a medical assessment that considers how severe the symptoms are, fever and blood in the stool.
When should I see a doctor?
If there is blood in the stool, high fever, signs of dehydration or vomiting that keeps you from drinking, if it does not improve after 3 days, or if you are pregnant, older or have a chronic condition.
Sources
- Connor BA, Leung DT. Travelers' Diarrhea. In: CDC Yellow Book 2026: Health Information for International Travel. Centers for Disease Control and Prevention; 2025. cdc.gov
- Chard AN, Hill V. Food and Water Precautions for Travelers. In: CDC Yellow Book 2026: Health Information for International Travel. Centers for Disease Control and Prevention; 2025. cdc.gov
- World Health Organization (WHO). Diarrhoeal disease. Fact sheet, March 7, 2024. who.int
- Centers for Disease Control and Prevention (CDC). Preventing Shigella Infection While Traveling. 2024. Accessed October 19, 2026. cdc.gov
- Galang RR, Roy SC. Pregnant Travelers. In: CDC Yellow Book 2026: Health Information for International Travel. Centers for Disease Control and Prevention; 2025. cdc.gov