Robin considered herself a seasoned traveler. She'd been south of the border before, so when she visited a friend in Mexico City, she knew better than to drink the water. But she let her guard down at a dance club in Acapulco and had a drink "on the rocks." She spent the next seven hours on a bus battling Montezuma's Revenge. "The discomfort was excruciating," says the 30-something writer from Arkansas.

Traveler's diarrhea is the most common illness affecting travelers. Bacterial infections (in many cases a strain of E. coli) cause most cases of traveler's diarrhea (TD), but viruses and parasites may also be culprits. Travelers who ingest contaminated food or drink may experience a range of symptoms—including urgency, watery diarrhea, nausea, vomiting, fever, and abdominal pain—that typically last for 3-7 days.

Location, Location, Location

Visitors to developing countries, most notably in Latin America, the Middle East, Asia, and Africa, put themselves at increased risk of TD, according to the United States Centers for Disease Control and Prevention (CDC). TD goes hand in hand with poor sanitation and poor refrigeration, says David N. Taylor, MD, director of the division of communicable diseases and immunology at the Walter Reed Army Institute of Research. He advises travelers to use common sense when determining where and what to eat while abroad. For example, five-star hotels that cater to foreigners are generally safer bets than open-air markets.

"If you're going to be eating with locals on the corners in Bangkok, then you're at high-risk," says Dr. Taylor, who experienced his worst bout of TD after enjoying a street festival in Peru.

Prevention

For travelers who don't want to limit their destinations, a healthy dose of awareness can lower their risk of TD. Here are some tips when visiting high-risk locations:

  • Do not drink tap water or add ice cubes. Drink only bottled water or, if necessary, local water that you have boiled for 10 minutes or treated with iodine or chlorine. Bottled carbonated beverages, steaming hot tea or coffee, wine, and beer are all okay to drink.
  • Use iodine tablets, such as Potable Aqua, to disinfect tap water.
  • Brush your teeth using bottled, boiled, or iodine-treated water only.
  • Avoid eating foods from street vendors or unhygienic eating establishments.
  • Avoid raw foods, especially salads and fruits (unless you can peel them yourself).
  • Avoid cooked food that has been sitting out in the open, even if it's re-heated. Food still hot from an oven is generally safer.
  • Avoid seafood from tropical reefs, some of which can be toxic even after thorough cooking.
  • Feed children six months and younger breast milk or formula prepared with sterilized water.

Before You Go

It's a good idea to see your doctor to get medicines before you go. Dr. Taylor prescribes travelers a supply of antibiotics (typically ciprofloxacin, or Cipro) and advises them to take along antidiarrheal medicine (such as Imodium).

Treat It Right Away

Dr. Taylor recommends that, at the first sign of diarrhea, travelers begin a two- to three-day course of antibiotics and take antidiarrheals medications as needed for more immediate relief. "You don't get any gold stars for holding off on treatment," he says.

He cautions against giving antidiarrheal medicine to young children. Young children with diarrhea should see a doctor early on, because they are at higher risk for dehydration than adults. For mild to moderate diarrhea in children, keep the child well-dehydrated with clean water or an electrolyte replacement product such as Pedialyte. If the child's diarrhea is severe (10 or more watery stools per day) or the child is urinating less frequently (a sign of dehydration) seek medical care immediately.

Prevention Tips

The Infectious Disease Society of America (IDSA) has made recommendations to prevent TD. Some recommendations include:

  • Taking medicines such as fluoroquinolones (eg, ciprofloxacin or norfloxacin); bismuth subsalicylate (eg, Pepto Bismol); or rifaximin
  • Avoiding:
    • Foods that are not steaming hot
    • Raw vegetables and fruit (unless personally peeled)
    • Fresh salads
    • Unpasteurized dairy products
    • Cold sauces and toppings
    • Open buffets
    • Undercooked or incompletely reheated foods
    • Fruit juices, tap water, and ice

If you have a trip planned, talk to your doctor about these and other recommendations.

Stay Hydrated With Safe Fluids

When TD strikes, travelers who want to salvage valuable trip time need to do more than just take medicine. Staying well-hydrated by drinking plenty of safe fluids is also essential. While this is true for everyone, it is especially important for pregnant women and children, in whom dehydration can have a more immediate and debilitating effect. Dehydrated travelers can also find relief using oral rehydration salts (ORS), widely available in developing countries. However, ORS should not be used as a substitute for clean, plentiful water.

When to Get Help

Seek immediate medical care for TD in any of the following situations:

  • Vomiting or diarrhea doesn’t go away after a couple of days
  • Symptoms don't subside after 3-7 days and/or after antibiotic treatment
  • Dizziness or lightheadedness
  • Worsening pain
  • High fever and/or disorientation
  • Stools are bloody and/or contain mucus
  • Signs of dehydration, such as decreased saliva or urination
  • Rapid, irregular heartbeat; chest pain
  • You are pregnant or caring for a young child who develops diarrhea

In some cases, TD can persist despite antibiotic treatment. Rarely, it can trigger other gastrointestinal problems. See your doctor if symptoms do not resolve after you return home.