Causes of diarrhoea and vomiting

Gastroenteritis inflames the stomach and bowel, often because of a virus or another infection. Food poisoning can cause a similar response after contaminated food or drink. Giardiasis may lead to prolonged digestive upset, particularly after unsafe water exposure. A food intolerance can trigger symptoms after a particular food, while Crohn's disease, coeliac disease, or irritable bowel syndrome may cause recurring bowel symptoms.

The combination can quickly remove fluid and salts. Pay attention to thirst, dry mouth, dizziness, weakness, urine becoming much less frequent, and whether any drink stays down. The timing of symptoms, recent meals, travel, sick contacts, new medicines, and abdominal pain can help a clinician assess the cause.

Take small, frequent sips of water or oral rehydration solution; large drinks may trigger more vomiting. Once fluids stay down, try light foods in small portions. Rest, wash hands thoroughly, and avoid preparing food for others while infection is possible. Do not take anti-diarrheal or anti-vomiting medicines for a child, during pregnancy, or with significant pain or blood in the stool without medical advice.

Seek urgent care for blood or coffee-ground material in vomit, black or bloody stool, severe abdominal pain, a swollen abdomen, fainting, confusion, breathing difficulty, or inability to keep even small sips down. Prompt assessment is needed for signs of dehydration, persistent symptoms, high fever with marked weakness, or illness in someone at higher medical risk.

Ask whether infection, food poisoning, a food reaction, medicine effect, or a longer-term condition fits the pattern, whether tests are needed, and how to replace lost fluid safely.