Travellers' diarrhoea is the most common illness affecting people travelling abroad, especially to parts of the world where food and water hygiene are harder to guarantee. For most people it is unpleasant but short-lived. Knowing how to reduce your risk, what to pack, and when a bout needs more than rehydration can make the difference between a lost afternoon and a ruined trip. This guide walks through prevention and the treatment options used in the UK.
What travellers' diarrhoea is and where the risk is highest
Travellers' diarrhoea means three or more loose stools in 24 hours, often with cramps, nausea, bloating or urgency, developing during or shortly after travel. Most cases are self-limiting bacterial infections caught from contaminated food or water, though viruses and, less commonly, parasites can also be responsible. The large majority resolve on their own within three to five days, even without specific treatment.
Risk is highest in parts of South Asia, Africa, the Middle East, and Central and South America, and it rises with adventurous eating, street food and poor local sanitation. It tends to strike in the first week of a trip, when your gut meets unfamiliar organisms. Understanding that the source is almost always something you have eaten or drunk is the key to prevention, and it also explains why even careful travellers sometimes catch it — a single contaminated meal or drink is enough.
Prevention — food, water and hand hygiene
The mainstay of prevention is careful food and water choices. The familiar advice to "boil it, cook it, peel it or forget it" still holds: favour food that is freshly and thoroughly cooked and served piping hot, fruit you peel yourself, and drinks that are sealed, bottled or boiled. Be wary of ice, salads and raw vegetables washed in local water, unpasteurised dairy, shellfish, and food that has been left standing at buffets or on market stalls.
Scrupulous hand hygiene makes a real difference — wash with soap and water before eating and after using the toilet, and carry an alcohol-based hand gel for when that is not possible. For drinking water where the supply is uncertain, stick to sealed bottled water, or boil, filter or chemically treat it, and use the same water for brushing your teeth. No preventive measure is perfect, but combining sensible food and water choices with good hand hygiene meaningfully lowers your risk.
It helps to plan ahead rather than improvise once you arrive. Packing oral rehydration salts, a hand sanitiser and any medicines your clinician has advised means you are ready if symptoms strike somewhere with limited pharmacy access. Knowing in advance which local food and drink to favour, and being cautious in the first few days while your gut adjusts, are simple habits that head off many episodes before they start.
Vaccines and pre-travel advice
There is no single vaccine that prevents most travellers' diarrhoea, because many different organisms can cause it. However, depending on your destination and itinerary, other travel vaccinations — for example against typhoid or hepatitis A, which are also spread through contaminated food and water — may be recommended as part of routine pre-travel planning. A pre-travel consultation is the place to review which vaccines and precautions suit your trip, alongside any medicines to carry.
Self-care — rehydration and when to use loperamide
The single most important part of self-care is replacing lost fluids and salts, because dehydration is the main danger, especially in hot climates. Oral rehydration is the core of treatment: oral rehydration salts dissolved in clean water replace both water and electrolytes far more effectively than water alone, and are well worth packing, particularly if you are travelling with children or older relatives. Sip steadily and keep going until symptoms settle, and continue eating light, plain food as your appetite allows.
For symptom control, loperamide can reduce the frequency of stools and is used symptomatically in adults without red flags — for example, to get through a long journey or an unavoidable commitment. It treats the symptom, not the infection, and should be avoided if you have a high fever or blood in your stools, as slowing the gut can be harmful in those situations. It is not recommended for young children. Rehydration remains the priority whether or not you use it.
When standby antibiotics are considered
Because most cases settle without them, antibiotics are not needed for the average bout. For selected higher-risk travellers — for instance, those with certain medical conditions, people who are immunosuppressed, or those heading somewhere remote with limited access to care — a clinician may provide "standby" antibiotics to carry and start only if a significant illness develops. Depending on the destination and individual factors, options such as ciprofloxacin or azithromycin may be considered, as resistance patterns vary by region and influence which antibiotic is suitable.
Standby treatment is a clinical decision made before you travel, taking account of where you are going, your health and your other medicines. It is not something to self-prescribe, and antibiotics are never a substitute for rehydration. A pre-travel consultation is the right place to discuss whether standby antibiotics are appropriate for you and how to use them safely if you do need them.
A word on probiotics
Some travellers ask about probiotics for prevention. The evidence is mixed and not strong enough to recommend them routinely, and they do not replace careful food and water choices. If you are considering them, it is reasonable to ask your clinician, but they are better regarded as a possible extra rather than a reliable safeguard.
Children and more vulnerable travellers
Some travellers need extra care. Young children, older adults, pregnant travellers and people with conditions such as diabetes, inflammatory bowel disease or a weakened immune system can become dehydrated faster and are more likely to run into trouble. For children in particular, oral rehydration salts are the priority, and loperamide is not recommended — the focus should be on fluids and seeking advice early if a child is not drinking, is passing very little urine, or seems drowsy or unusually irritable.
If you take regular medicines, a bout of diarrhoea and vomiting can affect how well some of them work, and a few — such as certain blood pressure or diabetes medicines — may need temporary adjustment during significant illness. This is worth raising at a pre-travel consultation so you know what to do if you become unwell abroad, rather than having to work it out on the road.
When to seek clinical review
Most episodes need nothing more than fluids and patience, but some warrant medical attention. Seek review if you have persistent diarrhoea lasting more than a few days, blood or mucus in your stools, a high fever, severe abdominal pain, or signs of dehydration such as marked thirst, reduced urination, dizziness or confusion. Diarrhoea that begins or continues well after returning home also needs assessment, as it can point to a parasitic cause that needs specific treatment.
Young children, older adults, pregnant travellers and people with underlying conditions should seek advice sooner, as they can become dehydrated more quickly. Occasionally, an episode of gastroenteritis can be followed by lasting bowel symptoms; our guide to IBS covers post-infectious patterns, and you may also find our acid reflux guide useful, or browse the Digestive Health category.
Working with your Farmeci clinician
Before a trip, a consultation can cover your destination, the length and style of your travel, your medical history and any regular medicines, and whether carrying oral rehydration salts, loperamide or standby antibiotics makes sense for you. If you are already unwell, a clinician can help judge whether your symptoms are settling as expected or need closer attention. The aim is practical, individualised advice that fits your journey, and your clinician will advise based on your individual circumstances.