What virus causes food poisoning?

Viruses can irritate the stomach and bowel after contaminated food, water, or contact with an infected person. Nausea, vomiting, loose stools, abdominal cramps, and fever may occur together. A viral cause is one explanation, not a diagnosis based on one symptom. Symptoms can overlap with bacterial illness and other conditions, so the timing of the illness, recent meals, travel, and contact with unwell people help a clinician assess it.

The main short-term concern is dehydration. Dry mouth, unusual thirst, dark urine, passing urine less often, dizziness, or marked weakness can signal that fluid loss is becoming significant.

Take frequent small sips of water or an oral rehydration solution; small amounts may be easier to keep down than a large drink. Continue with light foods when your appetite returns, such as rice, toast, bananas, or soup. Rest, wash hands carefully with soap and water, and avoid preparing food for other people while vomiting or having diarrhoea. Do not share towels or utensils. Oral Rehydration Therapy can help replace water and salts, while IV Fluid Therapy may be considered by a clinician when drinking is not enough.

Arrange prompt medical advice if you cannot keep fluids down, become confused or faint, pass very little urine, or have severe or worsening abdominal pain. Seek urgent help for blood in vomit or stool, a stiff neck, trouble breathing, or a severe illness in a baby, older adult, pregnant person, or someone with a weakened immune system. A clinician can decide whether testing, monitoring, or treatment is needed.

Could my symptoms fit a viral illness, and do I need testing? How should I use an oral rehydration solution? Which signs mean I should return urgently?