A practical timeline for diarrhoea
What usually happens, when to act, and how to avoid overtreatment or missed disease
Why a timeline helps
Diarrhoea fluctuates. A timeline helps you know what is normal, recognise deterioration early, and avoid unnecessary antibiotics and tests.
Day 0–1: Onset
- Start ORS immediately
- Rest
- Use antiemetics (ondansetron wafers) if vomiting prevents intake
Do not start antibiotics; do not use loperamide if fever or blood.
Day 2–3: Early course
Reassess urine output, ability to maintain fluids, fever/blood. Seek review if worsening, dehydrated, or vomiting persists.
Day 4–7: Persistent symptoms
Most viral/toxin illness improves. Consider stool testing if not improving; avoid repeated empiric antibiotics.
Day 8–14: Prolonged diarrhoea
Consider parasites, early IBD, medication-related diarrhoea, post-infectious dysfunction. Do targeted testing and review.
After 2–4 weeks: Chronic phase
Diarrhoea ≥4 weeks requires structured evaluation (see Chronic Diarrhoea).
After infection: what is normal?
Loose stools may persist for weeks; urgency/bloating common; microbiome recovery takes time.
Warning patterns at any time
Seek urgent care for blood/black stool, high fever, severe pain, reduced urine, confusion or collapse.
High-risk patients
Infants, older adults, pregnancy, immunosuppression, or asplenia: deterioration may be rapid; seek care earlier.
Key takeaway: Most diarrhoea follows a predictable course. Trust worsening symptoms — not the calendar.