Long-term effects of food poisoning

Food poisoning is an infection or irritation caused by contaminated food or drink. After the original illness settles, the bowel can remain sensitive, with loose stools, urgency, cramps, nausea, or bloating. Some people develop temporary difficulty digesting particular foods, while others have post-infectious bowel symptoms. Ongoing vomiting, fever, blood in the stool, or weight loss needs a fresh assessment rather than being assumed to be part of recovery.

Continuing symptoms can also reflect another infection, medication effect, inflammatory bowel disease, or a condition unrelated to the original meal. The timing, severity, travel history, and other affected people can help a clinician work out the next step.

Replace fluids regularly, using oral rehydration therapy if diarrhoea or vomiting has caused fluid and salt loss. Take small sips if nausea makes drinking difficult, and reintroduce simple foods as tolerated. Keep a brief record of stool frequency, pain, fever, vomiting, and foods that worsen symptoms. Avoid self-treating persistent diarrhoea with medicines if you have fever or blood in the stool; ask a clinician first. IV fluid therapy may be considered when drinking cannot maintain hydration.

Get urgent help for severe abdominal pain, blood or black stool, confusion, fainting, repeated vomiting, inability to keep fluids down, or signs of significant dehydration. Arrange a GP review when diarrhoea, nausea, altered bowel habits, fever, or fatigue does not steadily improve. Children, older adults, pregnant people, and those with long-term conditions may need earlier advice.

Ask whether you need stool tests, blood tests, or a review of medicines. Discuss hydration, foods to reintroduce, warning signs, and whether persistent symptoms could represent post-infectious bowel sensitivity or another diagnosis.