Traveler's Diarrhea

Causes

Traveler's diarrhea is spread by the fecal-oral route, through food or water contaminated with stool. Causes include:

• bacteria (80 to 90 percent): enterotoxigenic E. coli (ETEC), the most common, plus Campylobacter, Shigella, Salmonella and others
• viruses: norovirus, especially on cruise ships, and rotavirus
• parasites: Giardia, Cryptosporidium and Entamoeba histolytica, more often when diarrhea lasts longer than 2 weeks

Risk factors

• travel to areas with limited sanitation and water treatment
• eating food from street vendors, buffets, raw or undercooked meat and seafood, unpasteurized dairy, raw salads and unpeeled fruit
• drinking tap water or ice made from it
• young adults and adventurous travelers
• stomach acid-reducing medicines
• weakened immunity, diabetes or inflammatory bowel disease

Symptoms

Symptoms typically start within the first week of travel, but can occur any time during or shortly after:

• sudden, frequent, loose or watery stools (diarrhea)
• belly cramps (abdominal cramping)
• urgency
• nausea, sometimes vomiting
• bloating
• low-grade fever in some

Signs of more severe illness include high fever, bloody diarrhea (dysentery) and severe cramps.

Severity

Treatment

Rehydration

The most important treatment, because dehydration is the main danger. Drink plenty of safe fluids:

• oral rehydration solution (ORS): the best choice for moderate fluid loss, especially for children and older adults. ORS packets can be bought before travel or locally
• bottled water, broths and diluted juices for mild cases
• continue eating light foods as tolerated

Over-the-counter medicines

• loperamide slows the bowel and reduces the number of stools. Follow the label dose. Do not use if you have a high fever or bloody stools, and not for young children unless a doctor advises it
• bismuth subsalicylate reduces stools modestly and can be used for prevention. It turns the tongue and stools black. Avoid if you are allergic to aspirin, taking blood thinners, pregnant, or in children and teenagers because of the salicylate

Antibiotics

For moderate to severe diarrhea, a single dose or short course of antibiotics shortens illness:

• azithromycin: the preferred choice for dysentery, fever, or travel to South and Southeast Asia where resistance to other antibiotics is common. Suitable for children and pregnancy
• rifaximin: for non-invasive diarrhea, not for fever or bloody stools
• fluoroquinolones (ciprofloxacin, levofloxacin) are now used less because of resistance and side effects

Many travel clinics prescribe a standby antibiotic to carry. Use it only as directed.

When diarrhea persists after travel

Diarrhea lasting more than 2 weeks may be caused by parasites such as Giardia, and needs stool testing. Some people develop post-infectious irritable bowel syndrome, with ongoing bloating, cramps and changed bowel habits for months after the infection.

Prevention

Food and water

The traditional rule is "boil it, cook it, peel it, or forget it":

• drink bottled, boiled or properly treated water, and avoid ice unless made from safe water
• eat food that is cooked thoroughly and served hot
• peel fruit yourself
• avoid raw salads, undercooked meat and seafood, and unpasteurized dairy
• be cautious with street food and buffets where food sits at room temperature

Hygiene

• wash hands with soap and water before eating and after using the bathroom
• carry alcohol-based hand sanitizer (less effective against norovirus)

Medicines

• bismuth subsalicylate taken regularly can reduce the risk, for trips up to about 3 weeks, for adults who can safely take it
• preventive antibiotics are generally not recommended, except for some high-risk travelers
• vaccines: the cholera vaccine is available for some travelers. Typhoid and hepatitis A vaccines prevent other food- and water-borne diseases

Frequently asked questions

How long does traveler's diarrhea last?

Most cases last 1 to 5 days, even without treatment. Antibiotics can shorten moderate to severe illness to about a day. Diarrhea lasting more than 2 weeks needs medical assessment for parasites or other causes.

What is the best treatment for traveler's diarrhea?

Rehydration with fluids and oral rehydration solution is the foundation. Loperamide or bismuth subsalicylate helps mild to moderate symptoms. Azithromycin is the usual antibiotic for severe diarrhea, fever or bloody stools.

Should I take antibiotics for traveler's diarrhea?

Not for mild cases. Antibiotics are recommended for moderate to severe diarrhea, high fever or blood in the stool. Overuse contributes to resistance and side effects, so follow your travel doctor's advice on standby antibiotics.

How can I avoid traveler's diarrhea?

Drink safe bottled or treated water, avoid ice and tap water, eat hot, thoroughly cooked food, peel fruit yourself, avoid raw salads and unpasteurized dairy, and wash your hands often. Bismuth subsalicylate can reduce risk for some adults.