How to Avoid Bali Belly: Is Bali Tap Water Safe and What Should You Eat?

What causes Bali belly?

According to the CDC, bacteria are the most common cause of travelers' diarrhea, led by diarrhea-causing strains of E. coli, followed by Campylobacter, Shigella and Salmonella. Viruses such as norovirus cause fewer cases (often with more vomiting), and parasites such as Giardia are less common but can cause illness that lingers for weeks.

The CDC is also frank that the old rule "boil it, cook it, peel it, or forget it" helps but doesn't guarantee anything: travelers who follow it can still get sick, and poor kitchen hygiene is a major factor. Untreated bacterial diarrhea usually lasts 3 to 7 days, and viral diarrhea 2 to 3 days.

Can you drink tap water in Bali?

No. Bali's tap water isn't treated to drinking-water standards, and locals generally drink bottled, filtered or boiled water themselves. The CDC's guidance is to drink only beverages that are sealed, boiled, chlorine-treated or otherwise known to be purified. Check that bottle caps are sealed, and use bottled or filtered water to brush your teeth if you want to be cautious.

Ice and fresh juices are only as safe as the water they're made from. Established cafés and restaurants in tourist areas typically buy commercially made ice, but if you can't tell where the ice or the juice water came from, skip it.

To cut down on plastic, use refill stations: the RefillMyBottle app and map (it started in Bali as RefillBali) lists hundreds of cafés, shops and hotels that refill bottles with filtered water for free or a small fee. Many guesthouses and villas also keep a large refillable drinking-water dispenser for guests. Avoid swallowing water when swimming in rivers or pools as well.

Street food and warungs: how to eat safely

You don't need to avoid warungs (small local eateries); you need to choose them well. Favor busy places with high turnover, food that's cooked to order and served steaming hot, and fruit you peel yourself. Be more cautious with buffet trays that have sat out, raw salads washed in tap water, and undercooked seafood or meat.

Wash your hands with soap before eating, and carry hand sanitizer with at least 60% alcohol for when there's no sink, as the CDC recommends.

What to pack for Bali belly

Oral rehydration salts (ORS). The CDC calls replacing lost fluids the key to treatment. ORS packets are mixed with boiled or treated water; sugary soft drinks can make diarrhea worse. They're light, cheap and worth having before you need them.

Loperamide (Imodium) reduces how often you need to go, which helps on travel days, but the CDC advises not using it on its own if you have bloody diarrhea or a fever. Bismuth subsalicylate (Pepto-Bismol) can also help, but it isn't recommended for children under 3, pregnant women, or people allergic to aspirin or on blood thinners, and it can turn your tongue and stool black.

Some doctors prescribe a standby antibiotic for travelers to take if symptoms become severe. That's a decision for your own doctor before the trip, not something to improvise. While you're there, ask about vaccines: the CDC recommends hepatitis A for unvaccinated travelers to Indonesia aged one and over, and typhoid for most travelers. Our vaccines and health prep guide covers how far ahead to book that appointment.

When to see a doctor, and why travel insurance matters

CDC guidance says to see a doctor if you have bloody diarrhea, diarrhea lasting more than 3 days, a fever above 102°F (38.9°C), vomiting so often you can't keep liquids down, or signs of dehydration such as passing very little urine, a very dry mouth or dizziness when standing up. A child who seems dehydrated, has a fever or has bloody stools needs medical attention straight away.

Bali has international-standard clinics and hospitals, but treatment, and especially an IV drip or hospital stay, is billed to you. Check that your policy covers medical treatment abroad before you fly; our travel insurance guide explains what to look for.

For the rest of your trip, see our Ubud guide, the 10-day Bali itinerary and our Bali airport arrival guide.

Frequently asked questions