Water, food and staying well on the road

Gastrointestinal illness is by a wide margin the most common health problem travellers experience, and most of it is mild, self-limiting and manageable.

The scale

Studies of travellers to higher-risk destinations find that a substantial proportion — frequently cited around a third to a half depending on destination and duration — experience diarrhoea during a trip.

The great majority resolves within a few days without treatment.

A small proportion is more serious and warrants medical attention, and knowing which is which is the practically useful knowledge.

Water

Where tap water is not safe to drink, the precautions extend further than people remember.

Ice, which is frequently made from tap water.

Salads and raw vegetables washed in tap water.

Fruit that has been peeled by someone else or has been washed.

Brushing teeth, which many people continue to do with tap water out of habit.

Bottled water is the standard answer, with the sustainability cost being substantial and a filter bottle or purification tablets being an alternative worth considering.

Boiling is effective. Filtration and chemical treatment each have limitations regarding which organisms they address, and a combined approach covers most.

Food

The reliable principles.

Food cooked thoroughly and served hot is the safest category.

Food that has been sitting at ambient temperature is the least safe, which applies to buffets as much as to street stalls.

High turnover matters more than the appearance of the premises, which is why a busy street stall is frequently safer than a quiet restaurant.

Fruit you peel yourself is safe.

Raw and undercooked foods, unpasteurised dairy and shellfish carry higher risk in most settings.

Hand hygiene before eating matters considerably and is easy to neglect where washing facilities are limited — carrying sanitiser addresses this.

Managing it when it happens

The practical sequence.

Rehydration is the priority. Oral rehydration salts are the single most useful item to carry, and they are more effective than water alone because they replace electrolytes.

Sachets are inexpensive, weigh nothing and are available at pharmacies worldwide.

Eat when you can, starting with bland, starchy food. Prolonged fasting is not recommended.

Anti-motility medication can reduce symptoms and is generally avoided where there is fever or blood, since it may prolong certain infections.

Antibiotics are appropriate for some cases and are increasingly not recommended for mild illness, given resistance concerns and the fact that most cases resolve without them.

Guidance on carrying standby antibiotics has become more restrictive, and it is a decision for a travel health clinician rather than a default.

When to seek medical care

The indicators that warrant attention rather than waiting.

Fever, particularly high fever.

Blood in stool.

Severe abdominal pain.

Signs of significant dehydration — very reduced urination, dizziness, confusion.

Symptoms persisting beyond several days.

Illness in a young child, an older adult or anyone with a chronic condition, where the threshold should be lower.

And any fever in a region with malaria transmission, which requires urgent assessment regardless of other symptoms.

The other common problems

Dehydration and heat illness, particularly in hot climates where visitors underestimate fluid requirements.

Sunburn, which is more severe at altitude, near water and closer to the equator than people expect.

Altitude illness, which affects people unpredictably and which is managed by ascending gradually, resting on arrival at altitude, and descending if symptoms are significant.

Insect bites, and the diseases they transmit, discussed elsewhere on this site.

Motion sickness, for which several effective medications exist and which is better prevented than treated.

The preparation

A small kit covers most of this: rehydration salts, simple analgesia, an antihistamine, sunscreen, insect repellent, hand sanitiser and any personal medication.

Knowing where medical care is available at the destination before it is needed is worth ten minutes.

And having insurance with the details accessible, as discussed elsewhere on this site.

General information about travel health, not medical advice. Consult a travel health clinic or qualified clinician about your own circumstances, and seek medical attention for any concerning symptoms.