Can gastroenteritis cause dehydration?

Gastroenteritis inflames the stomach or intestines and may cause repeated loose stools, vomiting, fever, or reduced appetite. Each episode can remove fluid and electrolytes. Drinking may also be difficult when nausea is strong. Early dehydration can cause thirst, a dry mouth, darker urine, headache, dizziness, or unusual tiredness. Children, older adults, and people with other illnesses may deteriorate more quickly.

Take small, frequent sips rather than drinking a large amount at once. An oral rehydration solution can replace water and salts; follow the product instructions and use clean water. Continue breastfeeding if an infant is affected. When appetite returns, small portions of usual foods may be easier to tolerate. Avoid relying on alcohol or very sugary drinks, which may worsen fluid loss or nausea. A pharmacist or clinician can advise on the right product, particularly for a young child or someone with kidney, heart, or other medical conditions.

Get urgent medical help for fainting, confusion, severe weakness, very little or no urine, inability to keep fluids down, blood in vomit or stool, or severe abdominal pain. Seek prompt advice if diarrhoea or vomiting continues, or if a child has no tears, a very dry mouth, sunken eyes, or fewer wet nappies. Severe dehydration may need supervised treatment and fluid given through a vein.

Ask which rehydration solution is suitable, how much to offer after each episode, which medicines to avoid, and what signs mean that home care is no longer enough.