Most cases of Montezuma’s revenge, the traveler’s diarrhea common in Mexico and Latin America, resolve within three to five days without any special treatment. The priority is replacing lost fluids, managing symptoms so you can function, and knowing when the illness needs more than self-care. Here’s how to handle it step by step.
What Causes It
Bacteria cause the majority of cases. The most common culprit is a toxin-producing strain of E. coli found in contaminated water and food, followed by Campylobacter, Shigella, and Salmonella. Norovirus is the leading viral cause. Parasites like Giardia and Cryptosporidium are less common but tend to cause symptoms that drag on for weeks rather than days.
This matters for treatment because bacterial cases, which are the most likely scenario, respond well to over-the-counter remedies and sometimes antibiotics. Viral cases just need time. Parasitic infections typically need a specific prescription, so diarrhea lasting more than two weeks is worth getting tested.
Rehydration Comes First
Fluid loss is the real danger with Montezuma’s revenge, not the infection itself. Every loose stool pulls water, sodium, and potassium out of your body, and dehydration is what makes you feel truly awful: dizzy, weak, headachy, and foggy. Replacing those fluids is the single most important thing you can do.
Oral rehydration salts (ORS) are the gold standard. You can buy pre-mixed packets at pharmacies throughout Mexico and most developing countries. The WHO formula contains about 3.5 grams of salt and 20 grams of glucose dissolved in one liter of clean water, a ratio specifically designed to help your intestines absorb fluid as efficiently as possible. If you can’t find ORS packets, mix six level teaspoons of sugar and half a teaspoon of table salt into a liter of bottled or boiled water. It won’t taste great, but it works.
Sip steadily rather than gulping large amounts at once, which can trigger nausea. Sports drinks are better than nothing but contain more sugar and less sodium than ORS. Avoid alcohol and caffeine, both of which pull more water out of you.
Over-the-Counter Medications
Two widely available drugs can significantly reduce your symptoms while your body fights off the infection.
Bismuth subsalicylate (Pepto-Bismol) works as both an anti-inflammatory in the gut and a mild antimicrobial. For active symptoms, the recommended dose is 2 tablets (262 mg each) or 1 fluid ounce of liquid every 30 minutes, up to 8 doses in 24 hours. You can repeat that schedule on a second day. Your tongue and stools will turn black, which is harmless. Don’t use it if you’re allergic to aspirin or already taking blood thinners, since bismuth subsalicylate is chemically related to aspirin.
Loperamide (Imodium) slows down your intestinal contractions, giving your gut more time to absorb water from stool. The maximum over-the-counter dose for adults is 8 mg per day (typically a 4 mg starting dose followed by 2 mg after each loose stool). It brings fast relief and is especially useful when you need to get on a bus or a plane. However, avoid loperamide if you have a high fever or bloody stools, because in those cases slowing the gut down can trap a more serious bacterial infection inside.
You can use both medications together. Loperamide stops the urgency; bismuth subsalicylate calms the cramping and nausea.
When Antibiotics Help
For moderate to severe cases, where you’re having more than four loose stools a day or you’re in significant discomfort, antibiotics can cut the illness short dramatically, often to less than 24 hours. Doctors commonly prescribe azithromycin as a first-line option for travelers to Mexico and Latin America, partly because resistance to older antibiotics like fluoroquinolones has been rising. Another option, rifaximin, works well for non-invasive bacterial diarrhea (no fever, no blood in stool) because it stays in the gut rather than being absorbed into the bloodstream.
If you’re planning a trip to a high-risk destination, ask your doctor for a “just in case” prescription before you leave. Having antibiotics in your travel kit means you can start treatment the same day symptoms appear, which is when they’re most effective. Pairing a single dose of an antibiotic with loperamide often resolves symptoms within hours.
What to Eat During Recovery
When diarrhea is severe, stick to clear liquids only: broth, diluted juice, ORS, and water. Once you can keep those down and the frequency of stools starts dropping, gradually introduce bland, binding foods over the next one to three days.
The classic BRAT diet is a reliable guide:
- Bananas (high in potassium, which you’ve been losing)
- Rice (plain white rice, not fried)
- Applesauce (cooked, not raw apple)
- Toast (plain, no butter)
Salted crackers, plain noodles, baked potatoes, and clear soups are also safe early choices. The salt in crackers and broth helps your body hold onto the water you’re drinking.
Avoid dairy products for at least a few days after recovery. Diarrhea temporarily strips your intestinal lining of the enzyme that breaks down lactose, so milk, cheese, and yogurt can trigger a relapse of symptoms even after the infection is gone. Also steer clear of spicy foods, red meat, citrus fruits, tomatoes, raw vegetables, and anything fatty or fried until your gut feels fully normal again.
Preventing It in the First Place
The classic advice of “don’t drink the water” is a simplification, but the core idea holds. In Mexico and other high-risk areas, stick to bottled or purified water, skip ice in drinks unless you’re at a place that uses purified ice, and avoid raw salads, unpeeled fruits, and street food with ingredients that have been sitting at room temperature. That said, even careful travelers get hit, because the bacteria can be on a plate rim or in a salsa you didn’t think twice about.
Bismuth subsalicylate also works preventively. A study of travelers taking two tablets four times daily (about 2.1 grams per day) found a 65% reduction in diarrhea over a three-week period. A lower dose of one tablet four times daily still offered 40% protection. That’s a lot of Pepto-Bismol to take every day, but for a short trip where getting sick would be genuinely disruptive, it’s a proven option.
Probiotics are sometimes recommended for prevention, but the evidence is inconsistent. Some strains may offer modest protection, but no specific probiotic has strong enough data to be a reliable recommendation.
Signs That Need Medical Attention
Most cases of Montezuma’s revenge are miserable but not dangerous. A few red flags change that picture. Seek medical care if you notice blood or mucus in your stool, a fever above 102°F (38.9°C) that doesn’t come down, symptoms lasting more than 48 hours without any improvement despite treatment, signs of significant dehydration (no urination for 8 or more hours, extreme thirst, dizziness when standing), or if you’re unable to keep any fluids down due to vomiting.
Bloody diarrhea with fever suggests an invasive bacterial infection like Shigella or Campylobacter, which typically needs targeted antibiotic treatment rather than just symptom management. Diarrhea persisting beyond two weeks raises the possibility of a parasitic infection like Giardia, which won’t clear on its own and requires a different class of medication.