Diarrhoea after travelling: what should you know?

Travel can expose you to germs in food or water that your body has not encountered before. Food poisoning and gastroenteritis may start suddenly, while giardiasis can cause longer-lasting loose stools, gas and bloating. New foods, alcohol, stress and a changed routine can also disturb digestion. If symptoms continue beyond the travel episode or recur at home, a clinician may consider food intolerance, irritable bowel syndrome, coeliac disease, Crohn's disease or hyperthyroidism. A travel history, including destinations and timing, helps guide assessment.

Use safe drinking water and take small, frequent sips; oral rehydration solution can replace water and salts when losses are substantial. Eat simple foods as appetite returns and avoid alcohol, rich meals and anything that clearly aggravates symptoms. Wash hands with soap, clean the toilet and avoid preparing food for others while diarrhoea continues. Write down the onset, travel route, meals, fever, vomiting, blood and medicines. Do not start leftover antibiotics, because the cause may not need them and treatment choices depend on the illness.

Seek urgent care for blood or black stools, severe abdominal pain, confusion, fainting, repeated vomiting or very little urine. Contact a clinician promptly if diarrhoea is persistent, follows antibiotics, is accompanied by fever, or affects a child, older adult or person with reduced immunity. Tell the clinician where you travelled and when symptoms began; stool testing may be useful when infection is prolonged or severe.

Could this be an infection acquired during travel? Do I need stool testing? Which rehydration fluid is suitable? When can I return to work, exercise or food preparation?