Food poisoning pathophysiology

After contaminated food or drink is swallowed, an organism may attach to the gut lining, multiply, invade tissue or release toxins. The intestine responds by moving contents faster and releasing extra water, which can produce diarrhoea and cramps. Irritation of the stomach and nervous system can trigger nausea and vomiting. Immune activity may cause fever and tiredness. Different causes act at different points, so symptoms can begin soon after exposure or later.

Replace the water and salts lost through loose stools or vomiting with frequent small sips. Oral rehydration therapy is useful when ordinary drinks are not enough to replace electrolytes. Eat when able, choosing foods that are gentle on the stomach, and rest. Do not force large drinks during active nausea. If the gut cannot absorb enough fluid or vomiting prevents drinking, a clinician may use IV fluid therapy.

Get urgent help for severe abdominal pain, blood in stool or vomit, confusion, fainting, very little urine, repeated vomiting or a concerning fever. Dehydration can progress more quickly in infants, older adults, pregnant people and those with significant medical conditions, so seek advice early for these groups. Symptoms that worsen rather than settle need review.

Ask how much fluid to take, whether your medicines need adjustment during vomiting or diarrhoea, and whether your symptoms warrant examination or testing.