How long does oral rehydration therapy take to work for traveller's diarrhoea?

Traveller's diarrhoea can continue to remove water and salts even after you begin drinking. Oral rehydration solution is designed to help the intestine absorb these losses; it does not treat every possible cause of diarrhoea. Improvement may show as less thirst, a less dry mouth, better energy and urine returning toward its usual pattern. Ongoing frequent stools or vomiting can delay recovery.

Use a sealed commercial sachet or product suitable for oral rehydration and follow its mixing directions with safe drinking water. Sip often, especially after each loose stool. If you vomit, pause briefly and try smaller sips. Eat light food when able and avoid alcohol. During travel, wash hands, choose safe water and seek local medical advice if the illness is severe or you have a condition that increases dehydration risk.

Seek urgent care for fainting, confusion, severe weakness, breathing difficulty, blood or black stool, high fever with marked illness, or severe abdominal pain. Contact a clinician if you cannot keep fluid down, urinate very little, or remain dizzy despite drinking. Medical review is also sensible when diarrhoea persists after returning home or affects a young child, older adult or pregnant traveller.

Ask which rehydration product is appropriate at your destination, whether you need testing or other treatment, and how to recognise dehydration when access to care is limited.