Most cases of diarrhea are preventable with a handful of habits centered on hygiene, food safety, and gut protection. Diarrheal diseases still cause nearly 1.7 billion cases in children alone each year worldwide, and adults in every country deal with bouts triggered by contaminated food, unsafe water, antibiotics, and travel. The good news: the steps that actually work are straightforward and well supported by evidence.
Handwashing Is the Single Biggest Factor
Proper handwashing reduces diarrheal illness by 23 to 40 percent. That’s a larger effect than many people expect from something so simple, but hands are the main vehicle that moves pathogens from contaminated surfaces into your mouth. The key is duration: scrubbing with soap and water for about 20 seconds removes significantly more germs than a quick rinse. Wash before eating, before preparing food, after using the bathroom, and after changing a diaper.
When soap and water aren’t available, a hand sanitizer with at least 60 percent ethanol or 75 percent isopropanol will kill most bacteria and many viruses on contact. Sanitizer is a solid backup, but it doesn’t work well on visibly dirty or greasy hands, so washing remains the first choice.
Cook, Store, and Handle Food Safely
Undercooked meat and mishandled leftovers are among the most common triggers for foodborne diarrhea. A food thermometer takes the guesswork out of cooking:
- Poultry (chicken, turkey, ground poultry): 165°F (74°C)
- Ground beef, pork, lamb, or bison: 160°F (71°C)
- Pork chops, steaks, and roasts: 145°F (63°C), then let the meat rest for 3 minutes before cutting
Between the fridge and the stove, bacteria multiply fastest in what food-safety experts call the “danger zone,” temperatures between 40°F and 140°F. In that range, bacterial populations can double in as little as 20 minutes. The practical rule: never leave perishable food at room temperature for more than 2 hours. If it’s a hot day above 90°F, cut that window to 1 hour. Refrigerate leftovers promptly.
Preventing Cross-Contamination
Raw meat juices on a cutting board can easily transfer bacteria to salad greens or bread prepared on the same surface. Use separate boards for raw meat and ready-to-eat foods, or wash the board thoroughly with hot soapy water between uses. For countertops and high-touch kitchen surfaces, a diluted bleach solution (standard household bleach at 3 to 6 percent concentration) or a 60 to 70 percent alcohol spray will kill most bacteria and viruses.
Wash Produce Before You Eat It
Fresh fruits and vegetables can carry bacteria from soil, irrigation water, or handling during transport. The FDA recommends rinsing all produce under plain running water while gently rubbing the surface. You don’t need soap, vinegar, or commercial produce washes. Rinse before peeling, not after, so your knife doesn’t drag surface bacteria into the flesh. For leafy greens like lettuce and cabbage, remove and discard the outermost leaves, which tend to carry the most contamination.
Protecting Yourself While Traveling
Traveler’s diarrhea is the most common illness among people visiting regions with limited water treatment and sanitation infrastructure. The classic advice, “boil it, cook it, peel it, or forget it,” still holds up. In areas where tap water quality is uncertain, stick to commercially bottled water from a sealed, factory-sealed container for drinking, brushing your teeth, and even rinsing food.
Hot beverages made with water that has just been boiled, like tea and coffee, are generally safe. Avoid ice in drinks unless you’re certain it was made from purified water. Fountain drinks and any beverage mixed with local tap water carry risk. Carbonated drinks, beer, and pasteurized juices served in sealed bottles or cans are safe choices.
On the food side, skip raw salads, uncooked vegetables, unpasteurized dairy, and raw or undercooked seafood. Fruits you peel yourself (bananas, oranges, mangoes) are safer than pre-cut fruit from a street vendor. Rinse the outside with safe water before peeling, since your hands transfer whatever is on the skin to the fruit inside. Fully cooked dishes served hot remain your safest bet.
Preventing Diarrhea During Antibiotics
Antibiotics kill harmful bacteria, but they also wipe out protective gut bacteria, which is why diarrhea is one of the most common side effects of antibiotic courses. Taking a probiotic alongside your antibiotics can lower that risk. Two strains have the strongest evidence: Lactobacillus rhamnosus GG and Saccharomyces boulardii, a beneficial yeast.
In clinical trials, Saccharomyces boulardii taken at 250 to 500 mg twice daily for the duration of the antibiotic course (typically 10 to 14 days) reduced the incidence of antibiotic-associated diarrhea. Lactobacillus rhamnosus GG showed similar benefits at doses around 10 to 20 billion colony-forming units per day. Look for these specific strain names on supplement labels rather than generic “probiotic blend” products, since the evidence is strain-specific. Starting the probiotic on the first day of your antibiotic course, rather than waiting for symptoms, gives you the best chance of prevention.
Vaccinations for Children
Rotavirus is the leading cause of severe diarrhea in infants and young children worldwide. Vaccines against it are given orally during infancy, typically as two or three doses depending on the formulation. In high-income countries, these vaccines are 85 to 98 percent effective at preventing severe rotavirus illness. In lower-income settings, effectiveness is lower (51 to 64 percent in clinical trials) but still prevents a significant share of hospitalizations. The WHO recommends the vaccine be given during routine childhood immunization visits.
Daily Habits That Add Up
Beyond the major strategies above, a few smaller habits reduce your overall risk. Drinking enough water supports healthy digestion and can help your body flush pathogens more efficiently. Eating fiber-rich foods like whole grains, vegetables, and legumes feeds the beneficial bacteria in your gut, making it more resilient against invaders. Avoiding excessive alcohol and very high-fat meals also reduces the odds of loose stools, since both irritate the gut lining and speed up transit time.
If you’re prone to stress-related digestive issues, it’s worth noting that chronic stress alters gut motility and can trigger diarrhea even without an infection. Regular physical activity, adequate sleep, and basic stress management all contribute to a calmer digestive system over time.