Diarrhea means passing loose or watery stools more often than is normal for you. Acute diarrhea is commonly caused by an infection and often improves within a few days. The main immediate risk is dehydration, particularly in babies, young children, older adults and people with certain long-term health conditions.
Common causes
Possible causes include viral or bacterial gastroenteritis, contaminated food or water, medications such as antibiotics, food intolerance and digestive conditions. Persistent or recurring diarrhea may need investigation for conditions such as inflammatory bowel disease, celiac disease or irritable bowel syndrome.
Self-care and hydration
- Drink small amounts frequently.
- Use oral rehydration solution when dehydration is a concern because it replaces water and important salts.
- Continue breastfeeding and offer children their usual feeds when tolerated.
- Eat when able. A highly restrictive diet is usually unnecessary.
- Wash hands thoroughly with soap and water and clean frequently touched surfaces to reduce spread when infection is suspected.
Ask a healthcare professional or pharmacist before using anti-diarrheal medication, especially for a child, during pregnancy, or when fever or blood in the stool is present. Antibiotics are not needed for most acute diarrhea and should be used only when prescribed for an appropriate cause.
Signs of dehydration
Warning signs include intense thirst, dry mouth, dark urine, urinating less than usual, dizziness, unusual tiredness and sunken eyes. In babies and young children, warning signs can include fewer wet diapers, poor feeding, unusual drowsiness or no tears when crying.
When to seek medical care
Seek medical advice if diarrhea persists, repeatedly returns, begins after recent antibiotic treatment or international travel, or affects a baby, frail older adult or person with a weakened immune system.
Prompt assessment is also important for blood or black stools, high fever, severe abdominal pain, repeated vomiting or worsening dehydration.
Seek urgent medical care if the person becomes confused or very drowsy, faints, cannot keep fluids down, passes little or no urine, or develops other signs of severe dehydration.
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Sources
Last reviewed: 4 September 2026
Medical disclaimer: This information is general and does not replace individual medical assessment, diagnosis or treatment.