Why Do Foreigners Get Diarrhea in China? (2026 Guide)

Almost all foreign tourists who have just arrived in China encounter a perplexing and uncomfortable problem: Even though they’re eating the same food that locals eat every day, why are they the only ones getting diarrhea?

On travel forums (such as Reddit), similar posts pop up all the time. Some ask, “Why do I get diarrhea from eating street-side breakfast in China, but locals are fine after eating the same thing?”

Others are puzzled: “I’m very careful with lunch and dinner—I only eat hot, freshly prepared food—so why do I have even more problems?” Behind all these questions lies the same issue: traveler’s diarrhea, commonly known as “traveler’s belly.”

On Reddit, it’s also jokingly referred to as “Bali Belly,” “Delhi Belly,” or “China Belly.”

This article will explain why this happens, what you can do to prevent it, and what to do if it does happen.

If you’re planning a trip to China or have just arrived, this article is for you.

Quick Debunking of Key Concerns Raised by Reddit Users

Before diving into the scientific explanation, let’s address the most perplexing questions from Reddit head-on:

1.“I had diarrhea just 15 minutes after eating a baozi. Do locals also rush home with diarrhea?”

No. Diarrhea that strikes within 15 minutes is usually not caused by a bacterial infection—it typically takes several hours to several days for bacteria to multiply in the intestines and trigger symptoms.

Immediate diarrhea after a meal is more likely caused by the buns being high in fat and moisture, or containing irritating seasonings like garlic or sesame oil, which trigger an overactive “gastrocolic reflex” in your intestines.

This is a normal physiological reflex—when the stomach expands after eating, it sends a signal to the colon to “speed up peristalsis.”

If your gut is naturally sensitive, this reflex can “overreact,” causing you to feel the urge to use the restroom immediately after eating. Locals are already accustomed to this balance of fat and moisture and these combinations of seasonings, so their reflexes aren’t as intense.

2.“Why do I get sick more easily the more I’m careful to eat only hot food?”

It’s because your gut normally lives in an extremely clean environment and is in a “pampered” state.

Hot food kills the vast majority of bacteria, but if trace amounts of new bacterial colonies are introduced through your utensils, dipping sauces, or unwashed hands, your overly sensitive and “untrained” gut immune system will still overreact.

The gut immune systems of locals undergo “real-world training” every day and have long since learned to coexist peacefully with these bacteria.

3.“Is taking probiotics every day or two effective?”

The effect is negligible. Building a gut microbiome barrier requires daily, consistent supplementation, and the bacteria need sufficient time to colonize the gut. Taking them only every day or two is insufficient to form an effective protective barrier.

If you decide to use probiotics for prevention, it’s recommended that you start taking them daily before you leave.

Why Does This Happen?—A Scientific Explanation of“Traveler’s Diarrhea”

What Is Traveler’s Diarrhea?

Traveler’s diarrhea refers to an acute gastrointestinal issue that occurs during or after travel, typically characterized by three or more episodes of loose or watery stools per 24 hours, often accompanied by symptoms such as abdominal pain, nausea, vomiting, or fever.

According to research statistics, approximately 10% to 40% of travelers have experienced traveler’s diarrhea, with most cases occurring during the first week of travel. In most cases, symptoms resolve on their own within 3 to 5 days.

Why do locals eat the same food without any problems, but I get diarrhea when I eat it?

This is the most perplexing—and most crucial—aspect of the entire issue.

The root cause is not that the food itself is “unclean,” but rather that your gut is “unfamiliar” with these bacteria.

The culprits behind traveler’s diarrhea are various pathogens—bacteria, viruses, parasites, and others—which enter the body through contaminated food and water.

According to medical research, 80% to 90% of traveler’s diarrhea is caused by bacteria, most commonly “enterotoxigenic E. coli” (ETEC), followed by Salmonella, Campylobacter, and Shigella, among others.

The key point is this: Locals have lived in the area for a long time and have developed a certain degree of immune tolerance to the bacteria commonly found in local food. Their gut microbiota and immune systems have been “trained” over many years and have learned to coexist peacefully with these bacteria.

As a newcomer, however, your gut is encountering these “foreign” bacteria for the first time. Before your defense system has a chance to react, symptoms of diarrhea appear.

It’s like someone who has never had a cold visiting a country with a flu outbreak for the first time—they aren’t “weak,” they simply lack immunity.

Why does“being overly cautious actually lead to more problems?

Many foreign tourists have had similar experiences: the more cautious they are, the more likely they are to fall ill. There is actually a scientific basis for this.

Studies show that people who are very particular about food hygiene in their daily lives are actually more prone to gastrointestinal issues than locals when they visit places with relatively unfamiliar sanitary conditions.

The reason is simple: your gut is usually exposed to a limited variety of bacteria and is relatively “clean,” so your immune system is in a state of “pampered comfort.”

Once you enter a completely new microbial environment and face a large number of unfamiliar bacteria, your gut is like an army that has never been to battle—it’s completely defenseless.

Your problem isn’t that you’re “not careful enough,” but that you’re “too clean”—your gut hasn’t been “trained” to deal with these bacteria.

What Other Factors Increase the Risk?

In addition to bacterial infections, factors such as the physical exhaustion of travel, irregular sleep patterns, and high stress levels can also weaken your immune system, making it easier for pathogens to take advantage of your vulnerability.

During the first few days after arriving in China, jet lag, rushing from place to place, and excitement—all of these can leave your body in a state of “low defense.” Additionally, changes in the composition of the food itself may also cause your digestive system to “protest.”

What Should You Do?—A Comprehensive Guide for Before, During, and After Your Trip

In 2026, China released its first *Chinese Expert Consensus on the Prevention and Treatment of Traveler’s Diarrhea*, which proposed a comprehensive management framework covering“before, during, and after” the trip. The following is a complete set of recommendations compiled based on this framework and extensive practical travel experience.

Before Departure: Be Prepared

1. Understand the Risks

If you plan to stay in China for an extended period (e.g., more than 2 weeks) or if you have a sensitive digestive system, it is recommended that you consult a doctor before departure to understand the risks of traveler’s diarrhea and the necessary preventive measures.

2. Prepare an“Emergency Diarrhea Kit”

The expert consensus recommends that travelers planning a trip of 14 consecutive days or longer carry an“emergency diarrhea kit” containing:

Item	English/Brand Name	Description
Oral Rehydration Salts (ORS)	Oral Rehydration Salts (ORS)	Prevent dehydration—this is the most important thing. Available for purchase directly at Chinese pharmacies
Smecta / Montmorillonite Powder	Smecta / Montmorillonite Powder	Over-the-counter anti-diarrheal adsorbent, similar to Pepto-Bismol in the West
Loperamide (Imodium)	Loperamide (Imodium)	Anti-diarrheal medication that reduces the frequency of diarrhea. Can be purchased at Chinese pharmacies by providing the English name

3. Consider Getting Vaccinated

The oral cholera vaccine (rBS/WC vaccine) not only prevents cholera but also protects against toxigenic E. coli and certain other bacterial infections.

However, even if you’ve been vaccinated, you should still practice good food hygiene while traveling.

4. Start Taking Probiotics Daily Before Departure

For people with sensitive digestive systems, it is recommended to take probiotics daily starting before departure, rather than just every few days.

Studies show that certain strains of Lactobacillus can provide up to a 39% protection rate against traveler’s diarrhea.

But note: Probiotics are only a supplementary measure and cannot replace good food hygiene.

⚠️ Important Reminder: Do Not Take Antibiotics on Your Own as a Preventative Measure

The practice of “taking a few antibiotic tablets before departure as a preventative measure” is not advisable. Antibiotics indiscriminately kill both beneficial and harmful bacteria in the gut, disrupting the balance of the gut microbiota and potentially leading to bacterial resistance—which, if an infection does occur, will make it even harder to treat.

While in China: What to Eat and What to Avoid

Food Safety Checklist for Foreign Tourists in China

Risk Level	Safe to Eat	Avoid or Be Careful	Key Reason
Low Risk (Safe)	Hot noodle soup straight from the pot, piping-hot stir-fried dishes, white rice	Hot food that has been left to cool, lukewarm stews	High temperatures thoroughly kill the vast majority of pathogenic bacteria
Moderate Risk (Caution)	Fresh fruit you peel yourself (bananas, oranges, apples)	Pre-sliced fruit from street vendors, strawberries and blueberries that cannot be peeled	Bacteria can easily grow on the surface of pre-sliced fruit at room temperature, and the quality of the washing water is uncertain
High Risk	Unopened bottled water from well-known brands, boiled tea	Drinking tap water directly, ice made from tap water, raw or cold mixed salads from mobile street vendors	Your gut flora lacks tolerance for local water quality and microorganisms found in raw or cold foods

A simple, easy-to-remember rule:

> “Cooked, hot, and peelable”—stick to these three categories, and you’ll have far fewer digestive issues.

Regarding bottled water: Do not drink tap water directly—this is the point foreign tourists most often overlook. Bottled water is widely available in China and very inexpensive. Whether in big cities or small towns, please stick to drinking bottled water or boiled water.

For an explanation of why tap water is safe to use for brushing your teeth but not for drinking, please read this article [Can You Use Beijing Tap Water to Brush Your Teeth? A Practical Guide for Foreign Visitors (Tested in 2026)].

Tips to Avoid Pitfalls in China

Here are some details you won’t find in typical travel guides:

1. Free Tea at Restaurants

Most Chinese restaurants serve hot tea brewed with boiled water, which is relatively safe. However, if you have an extremely sensitive stomach, it’s best to ask for unopened bottled water instead.

2. Scalding Cutlery with Boiling Water—A Unique Chinese“Ritual”

Before eating at a street-side eatery, you might see locals rinsing their bowls and chopsticks with boiling water. The actual sterilizing effect of this practice is limited—the hot water provided by restaurants is usually less than 60°C, and rinsing for a few seconds isn’t enough to effectively kill bacteria.

However, it does rinse away surface dust and residual detergent. You can follow local customs and do the same, but don’t expect it to replace proper food safety measures.

3. Hand Hygiene—The Most Overlooked Step

When eating street food (such as steamed buns or pancakes), it’s often not the food itself that causes diarrhea, but rather handling it with unwashed hands.

Carry alcohol wipes or hand sanitizer with you, and wipe your hands before eating—this small habit can help you avoid a lot of trouble.

If You’ve Already Started Having Diarrhea: What to Do

Step 1: Don’t panic—most cases resolve on their own

Traveler diarrhea is usually self-limiting, and most people recover on their own within 1 to 5 days. As long as it’s not particularly severe, there’s no need to worry excessively.

Step 2: Staying hydrated is the top priority

The greatest danger of diarrhea isn’t the diarrhea itself, but dehydration and electrolyte loss.

– Drink oral rehydration solution (ORS)—available at pharmacies and very inexpensive

– If unavailable, drink lightly salted water or an electrolyte-containing sports drink

– A simple homemade recipe: 1,000 ml of water + 1 teaspoon of salt + 8 teaspoons of sugar

– Do not drink plain water alone—plain water cannot replenish lost electrolytes

Step 3: Adjust Your Diet

Follow the internationally recommended BRAT diet: Bananas, Rice, Applesauce, and Toast. In China, you can substitute these with easily digestible foods such as plain rice porridge, toasted slices of steamed buns, or noodles in clear broth.

– Avoid raw, cold, spicy, and greasy foods

– Avoid overeating; eat small, frequent meals

– Get plenty of rest

Step 4: Use Medication as Appropriate

– Montmorillonite Powder (Smecta / Montmorillonite Powder): An over-the-counter medication that adsorbs pathogens and toxins in the intestines

– Loperamide (Imodium): An antidiarrheal medication that reduces the frequency of diarrhea

– Note: If you have a fever or blood in your stool, do not take antidiarrheal medication on your own—this may trap pathogens in your body and worsen your condition

When Should You See a Doctor?

Seek medical attention immediately if any of the following symptoms occur:

– Diarrhea that lasts 3 to 5 days without improvement

– A fever higher than 38.5°C

– Blood or pus in the stool

– Severe abdominal pain or vomiting

– Signs of severe dehydration (dry mouth, decreased urine output, dizziness, weakness)

Elderly people, children, pregnant women, and those with chronic medical conditions should seek medical attention even sooner if they experience diarrhea.

If you’re experiencing these issues, don’t think of yourself as “overly sensitive” or “careless.” It’s not your fault—data shows that approximately 10% to 40% of travelers have experienced traveler’s diarrhea. It’s not that you have a “weak constitution”; it’s simply that your gut’s immune system hasn’t encountered these bacteria yet.

The good news is: as you spend more time in China, your gut will gradually build up a tolerance to these bacteria.

Many foreigners who have lived in China for a long time will tell you the same thing: “You’re prone to diarrhea for the first month or two, but then you gradually adjust.”

Until then:

– Drink bottled water

– Eat thoroughly cooked, hot food

– Carry oral rehydration salts with you

– See a doctor when necessary

We hope your trip to China goes smoothly—from your stomach to your spirits.