Traveller's Diarrhoea: The Pre-Trip Kit That Actually Changes Your Outcome

Up to 56% of travellers develop diarrhoea on a short trip. The right three items in your bag decide whether you lose a day or a week.

Traveller's diarrhoea: what your kit determines more than your destination

Between 20% and 56% of travellers on trips under 100 days develop traveller's diarrhoea. That is not a worst-case figure; it is the pooled estimate from a 2024 meta-analysis of 8,478 participants. Most cases are mild and self-limiting. The difference between losing one afternoon and losing four days almost always comes down to what you packed before you left.^[1]

This article gives you a pre-departure checklist, explains how to read your symptoms, tells you which destinations carry the highest risk, and sets out the three situations where you must stop self-treating and see a doctor.

Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Traveller's diarrhoea can occasionally signal a serious infection requiring prompt treatment. Always consult a doctor or travel medicine specialist before departure, and seek medical care if your symptoms include bloody stool, fever, or signs of severe dehydration.

Destinations where risk is highest

Destination is the single strongest predictor of your risk. The CDC Yellow Book 2026 rates India as one of the most hazardous destinations, estimating a greater than 60% likelihood of developing TD during a two-week trip to India. Mexico, Nepal, Guatemala, Peru, Egypt, and many countries across sub-Saharan Africa carry similarly elevated attack rates.^[2]

Timing matters within the same country. In South Asia, attack rates rise sharply during the hot months before the monsoon, when food-handling infrastructure is under the most stress. Expatriates in Kathmandu, Nepal, averaged 3.2 episodes per person in their first year, which shows that prior exposure does not protect you on a new trip.^[3]

The bacterial cause behind the illness also varies by region, and that affects which antibiotic works. In Thailand, India, Nepal, and Cambodia, Campylobacter is frequently resistant to fluoroquinolones such as ciprofloxacin.^[7] This is a practical reason to discuss destination-specific antibiotic choice with a travel medicine provider before you leave, not after you fall ill.

The three-item kit that changes your outcome

Most travellers pack nothing and then scramble for a pharmacy on a Sunday afternoon in a city they do not know. A three-item kit, assembled before departure, covers the vast majority of cases.

1. Oral rehydration salts (ORS). Dehydration, not the diarrhoea itself, is what puts people in hospital. ORS sachets replace sodium, potassium, and glucose lost through diarrhoea more effectively than plain water or sports drinks. Pack at least four to six sachets per person. Use bottled or purified water to mix them.

2. Loperamide. Loperamide reduces the frequency of loose stools and is useful when a bathroom is not accessible. It is a symptom-control tool, not a cure. The CDC advises against using loperamide alone for bloody diarrhoea or diarrhoea accompanied by fever. In those situations, it can prolong the illness by slowing the clearance of invasive bacteria. Rehydration always takes priority.^[4]

3. A standby antibiotic (prescription-only, arranged before departure). Current guidelines do not recommend taking an antibiotic for mild diarrhoea. But carrying one, prescribed by a travel medicine provider who knows your destination, means you can act quickly if symptoms escalate. Your prescriber will choose between azithromycin and rifaximin based on where you are going.

Reading your symptoms: mild, moderate, severe

Traveller's diarrhoea typically starts within one to three days of exposure and resolves within five days. Symptoms include loose or watery stools, abdominal cramps, nausea, and sometimes a low-grade fever. The CDC 2026 Yellow Book framework matches treatment to severity across three categories.

Mild: tolerable symptoms that do not stop you from your planned activities. Manage with ORS and rest. Loperamide is optional.

Moderate: distressing symptoms that are forcing you to cancel activities. ORS plus loperamide. This is the point where a prescribed antibiotic becomes reasonable if you have one.

Severe: incapacitating diarrhoea, high fever, bloody stool, or severe abdominal pain. Use your clinician-prescribed plan and seek medical care. Azithromycin is the preferred antibiotic for severe illness and for any destination where fluoroquinolone-resistant Campylobacter is prevalent.^[5] Our antibiotics travel guide explains how to travel with these medications correctly.

Three red flags that mean stop self-treating

Self-treatment is appropriate for the first 24 to 72 hours of a mild or moderate episode. Three specific signs require you to stop and seek medical evaluation: blood or mucus in your stool, fever alongside diarrhoea, or symptoms persisting beyond 72 hours. Each signals a possible invasive bacterial infection or a parasite that will not clear without specific treatment.^[6]

Persistent diarrhoea lasting more than a week requires stool microscopy to rule out Giardia, Cryptosporidium, and Cyclospora, none of which clear with loperamide or standard short-course antibiotics.

Dehydration progresses faster in hot climates. Dark yellow urine, a dry mouth, dizziness when you stand, or a rapid heartbeat are signs that ORS alone may not be keeping pace. In that situation, intravenous fluids at a clinic are faster and safer than trying to keep up orally. Use Nomedic's provider search to find English-speaking specialists and facilities at your destination.

Why the 'boil it, cook it, peel it' rule is not enough

The traditional advice to "boil it, cook it, peel it, or forget it" is a reasonable starting point but studies show that travellers who follow these rules still develop TD. Poor hygiene practices among food handlers in local restaurants, and inadequate sanitation infrastructure, carry risk regardless of how careful you are with your own choices.^[3]

This does not mean food caution is pointless. Street food from vendors with high turnover is often safer than restaurant food that has been sitting in inadequate refrigeration. Avoid raw shellfish, unpasteurised dairy, and salads washed in tap water. These categories carry the highest contamination risk at the point of preparation.

Hand hygiene before eating remains one of the most effective single interventions. Alcohol-based gel at 60% concentration or above is reliable when soap and water are unavailable.

Who is at higher risk

Young adults, backpackers, and those on longer trips face higher incidence than older travellers on shorter stays. Risk factors identified in the 2024 meta-analysis include younger age, longer travel period, and a backpacking travel style. Travel for tourism, as opposed to visiting family, also correlates with higher rates, most likely because tourists eat more widely and adventurously.^[1]

Immunocompromised travellers, those with inflammatory bowel disease, and those on H2-blockers or proton pump inhibitors face a higher risk of a severe episode because stomach acid normally kills many ingested pathogens. If you fall into these groups, the conversation with your travel medicine provider about a standby antibiotic is not optional.

Your pre-departure checklist

Book a travel medicine appointment at least four weeks before departure. Tell the provider your exact itinerary. Antibiotic choice depends on destination.

Pack ORS sachets, loperamide, and any prescription standby antibiotic in your carry-on, not checked luggage. You cannot use them on day two of a long flight if they are in the hold.

Know the three red flags before you land: bloody stool, fever with diarrhoea, and symptoms lasting more than 72 hours. Write them on a note in your phone if necessary.

Identify the nearest clinic or hospital at your destination before you need it. If your travel insurer has a 24-hour assistance line, save that number offline.

Store your medical records before you travel. Knowing your allergy history and current medications matters when a local doctor needs to prescribe quickly. Your Nomedic medical record is shareable in the IPS format, which emergency doctors in many countries can read directly. If you want to understand more about the clinical background of travellers' diarrhoea, the Nomedic glossary entry covers the definitions clinicians use.

Check if your travel insurance covers outpatient treatment for acute illness. Traveller's diarrhoea that requires a clinic visit with IV fluids or stool testing can cost well above €150 (~$176) at a private clinic in Thailand, Morocco, or Mexico.

Frequently asked questions

How long does traveller's diarrhoea usually last?

Most episodes resolve within three to five days without antibiotic treatment. If symptoms persist beyond 72 hours, especially with fever or blood in the stool, you should seek medical assessment rather than continuing to self-treat.

Can I buy ORS sachets in pharmacies abroad or should I bring them?

Oral rehydration salts are available at pharmacies in major cities in India, Mexico, Thailand, and Kenya, often sold as branded sachets like Electral or Dioralyte. That said, arriving ill on a Sunday in a rural area is a different situation. Pack at least four to six sachets from home to cover the first day or two wherever you land.

Should I take antibiotics as soon as I get diarrhoea abroad?

No. Current CDC 2026 Yellow Book guidance advises against antibiotics for mild cases. Reserve them for moderate symptoms that are disrupting your trip, or for any severe or febrile illness. Taking antibiotics unnecessarily accelerates resistance and can cause side effects without shortening a mild episode.

Is ciprofloxacin still a good choice for traveller's diarrhoea in Asia?

Not as a first choice. Campylobacter, a common bacterial cause of traveller's diarrhoea in India, Thailand, Nepal, and Cambodia, is frequently resistant to ciprofloxacin and other fluoroquinolones. Azithromycin is the preferred agent for those destinations and should be discussed with a travel medicine provider before departure.

Is it safe to use loperamide if I have a fever with diarrhoea?

No. Fever alongside diarrhoea suggests a bacterial or invasive infection where slowing gut motility can prolong the illness or mask worsening symptoms. Use oral rehydration salts, skip loperamide, and seek a medical review promptly.

What is the risk of getting traveller's diarrhoea in Mexico specifically?

Mexico is classified as a high-risk destination. Attack rates for a two-week trip are commonly reported in the 30% to 50% range, with the highest risk in southern regions with tropical climates and in areas outside major urban centres. The CDC Yellow Book 2026 lists Mexico as a destination where a standby antibiotic is worth discussing with your travel medicine provider.