Common Causes and Their Timelines
| Pathogen | Onset After Eating | Typical Duration |
|---|---|---|
| Staph aureus toxin | 1-6 hours | 24 hours |
| Norovirus | 12-48 hours | 1-3 days |
| Salmonella | 6-72 hours | 4-7 days |
| Campylobacter | 2-5 days | 1 week |
| E. coli (including O157) | 3-4 days | 5-10 days (can cause serious kidney complications) |
Home Management
- Fluid replacement is the priority — oral rehydration solutions, water, diluted squash
- Eat when able — small, plain meals (BRAT diet: bananas, rice, applesauce, toast) once tolerating fluids
- Avoid dairy, fatty, and spicy foods until recovering
- Rest
- Anti-diarrhoeal medications (loperamide) generally best avoided in suspected bacterial infection with fever/blood, as they can prolong illness
When to Seek Medical Care
| Sign | Concern |
|---|---|
| Blood in stool | Suggests bacterial cause needing assessment (especially E. coli O157) |
| High fever (>39°C) | May need assessment and possibly antibiotics |
| Signs of dehydration | Reduced urination, dizziness, dry mouth |
| Symptoms lasting >3 days without improvement | Needs review |
| Severe abdominal pain | Consider other causes (appendicitis) alongside infection |
| Recent travel with severe symptoms | May need specific testing/treatment |
E. coli O157 — Watch for Kidney ComplicationsBloody diarrhoea, especially in children, following E. coli O157 infection can rarely progress to haemolytic uraemic syndrome (HUS), a serious kidney complication — seek urgent medical assessment for bloody diarrhoea, particularly in young children, and avoid anti-diarrhoeal medication.
Handwashing Prevents SpreadFood poisoning, especially norovirus, spreads easily person-to-person. Thorough handwashing (soap and water — alcohol gel is less effective against norovirus), staying home while symptomatic, and avoiding food preparation for others helps prevent spread.
Should I take antibiotics for food poisoning?
Most food poisoning, including many bacterial causes, resolves without antibiotics, which can occasionally prolong certain infections (particularly E. coli O157) or cause resistance — antibiotics are reserved for specific situations determined by your doctor.
How long am I contagious after norovirus?
You remain contagious for at least 48 hours after symptoms resolve, and virus can be shed in stool for up to 2 weeks — good hygiene practices should continue during this period.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.