Diarrhoea in Children: Treatment, Feeding and Red Flags
Reviewed by the LabReadAI medical team
Diarrhoea is the second commonest reason children are brought to a paediatrician after respiratory infections, and the first cause of parental panic about "bad stool". Most episodes resolve on their own, and the outcome turns on one thing: whether the child kept up with fluid losses.
What counts as diarrhoea in children by age
The main error is comparing a child's stool with someone else's idea of normal.
| Age | Usual stool | What counts as diarrhoea |
|---|---|---|
| Breastfed | Up to 6–8 times a day, loose, yellow, with curds | Sharp increase from the usual, watery consistency, changed smell |
| Formula-fed | 1–4 times, thicker | Increase in frequency and looseness from the usual |
| Over one year | 1–2 times, formed | Three or more unformed stools in a day |
Hence the rule: in infants judge deviation from their own baseline, not an absolute number.
Diarrhoea with and without fever in children
Fever helps narrow the field. Diarrhoea with fever and vomiting is almost always acute gastroenteritis, usually viral: rotavirus and norovirus produce exactly this picture. Bacterial causes — see intestinal infection and salmonellosis — bring high fever, pain and blood.
Diarrhoea without fever shifts thinking elsewhere: dietary indiscretion, excess fruit juice and sorbitol, post-infectious lactase deficiency, an antibiotic reaction, parasitic causes — see giardiasis and testing for worms — and, in a chronic course with poor weight gain, coeliac disease.
When diarrhoea comes with vomiting, the rehydration technique is described in detail in vomiting in children.
How long diarrhoea lasts in children
Acute viral diarrhoea lasts 5–7 days, sometimes up to 10. The picture stops being ordinary when:
- diarrhoea lasts more than 14 days — now protracted, another cause is sought;
- diarrhoea returns immediately after recovery — often transient lactase deficiency;
- chronic loose stool with poor weight gain — grounds for planned investigation.
Green diarrhoea, mucus and blood in stool
Colour worries parents most and informs least.
- Green diarrhoea usually means fast transit: bile has no time to change on the way. Colour alone says nothing about severity.
- A little mucus occurs in any infection; copious mucus with blood is another matter.
- Blood in stool always warrants review: it occurs in bacterial infection, in an anal fissure from constipation, in cow milk protein allergy in infants and, rarely, in intussusception.
- Rice-water stool, copious and watery, is the picture of severe secretory diarrhoea and needs immediate care.
What other shades mean is covered in stool colour.
Dehydration with diarrhoea: what to count
The same as with vomiting: urine output, tears, mouth moistness, the fontanelle in infants, behaviour. The practical counter — no wet nappy in 8 hours — means a doctor rather than more observation. The reverse silence is also worrying: a child who has stopped asking to drink and become drowsy is losing fluid faster than it appears.
How to treat diarrhoea in children — and what does not work
| Remedy | What is known |
|---|---|
| Oral rehydration solutions | The basis of treatment, proven |
| Zinc (in deficient regions) | Shortens duration and severity in young children |
| Selected probiotic strains | May shorten diarrhoea by about a day; effect is strain-specific — see choosing a probiotic |
| Adsorbents | May reduce stool volume, do not change outcome |
| Loperamide and other anti-diarrhoeals | Not prescribed to children: risk of toxic megacolon |
| Antibiotics "just in case" | Not indicated: most diarrhoea is viral |
| Dysbiosis testing and its treatment | No diagnostic value — see stool dysbiosis testing |
Feeding a child with diarrhoea
Current advice is the opposite of the old habit: no starvation pause. Early return to normal age-appropriate feeding shortens diarrhoea and reduces weight loss. Breastfeeding continues without restriction.
Practical guidance: ordinary food in small portions; temporarily limit fruit juices and very sweet drinks, whose osmotic load worsens stool; strict elimination diets and diluting formula with water are unnecessary. Lactose-free formula is used only for proven post-infectious intolerance, not routinely.
When tests are needed
Not in an ordinary course. Investigation is ordered for blood in stool, fever above 39 °C, diarrhoea beyond two weeks, suspected parasites or dehydration. Usually stool microscopy and culture, stool testing for parasites, electrolytes when dehydrated, and in a protracted course a complete blood count with differential, whose paediatric ranges are covered in CBC in children.
If diarrhoea comes with severe abdominal pain, surgical causes must be excluded first — see abdominal pain in children. General conduct during fever is in fever in children.
This article is informational. Diagnosis and treatment are the paediatrician's task.
For informational purposes only
This article is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Please consult a healthcare professional for medical guidance.