The short answer
At 7–9 months, a wider range of solids can change the colour, smell and texture of your baby’s poo. Blood, pale or tarry black poo and significant diarrhoea need assessment.
In this guide · 12 sections
Keep in mind
- Different foods can change the colour and consistency of poo.
- Hard painful poo and sudden watery diarrhoea are different from everyday changes.
- Blood, pale or tarry black poo should be checked.
- Diarrhoea should not be assumed to be teething.
Why poo changes at 7–9 months
Your baby may have started solids at about six months. Between seven and nine months, a wider variety of vegetables, cereals, fruit and suitable proteins can also change what you see in the nappy.
A meal with lentils, broccoli and soft fruit may make poo look or smell different from the earlier milk-and-purée stage. However, do not attribute every change to food.
Which colours may be food-related?
Yellow, brown and green can all occur. Green vegetables may make poo greenish and beetroot may cause red tones. Remember what your baby ate, but do not assume red is harmless.
Very dark green poo can look black. Truly black, sticky or tarry poo, white, pale grey or clay-coloured poo, and unexplained blood need advice, even if your baby seems well.
Changes in texture and smell
As solids diversify, poo may become more formed and smell stronger. One softer nappy and another firmer one are not necessarily a problem; knowing your baby’s pattern is more useful than counting nappies alone.
You may notice small pieces of pea skin, sweetcorn or vegetable peel. These can reflect incomplete breakdown of some food and do not show that no nutrients were absorbed.
When loose poo may be diarrhoea
Breastfed babies often have soft poo. Diarrhoea is a sudden change to substantially more frequent, watery stools than usual, especially with vomiting or unusual tiredness.
Fewer wet nappies, a dry mouth, fewer tears or unusual drowsiness may suggest dehydration. Seek prompt assessment and generally continue breast milk or correctly prepared formula unless advised otherwise.
Is firmer poo constipation?
Not necessarily. Formed stools after introducing solids are not the same as constipation. Small hard dry pellets and pain when passing poo are more helpful clues.
A baby who misses a day and then passes soft poo comfortably is different from one who cries while passing hard pellets each day. The constipation guide explains more.
Does teething cause diarrhoea?
Teething and infections may happen when new foods are introduced. Their timing does not mean teething causes diarrhoea; the AAP does not list diarrhoea as an ordinary teething symptom.
Do not explain away frequent watery stools or fever as teething, especially with reduced feeds or a change in general wellbeing. Speak to a health professional.
Does every change mean an allergy?
A different colour or smell after a new food is not proof of an allergy. Food changes, fluid intake and minor infections can overlap.
Seek advice for blood in poo, repeated vomiting, hives or other clear reactions. Difficulty breathing or swelling of the tongue or throat is an emergency. Do not remove major food groups on your own.
What can you do today?
Note the texture, quantity and your baby’s general wellbeing as well as colour. Keeping track of recent foods can help you see a pattern rather than worry over one nappy.
A nappy photograph can help describe what you saw, but cameras alter colours and photos cannot establish a diagnosis. Do not delay medical advice for white, red or black appearances.
When to get medical help
White/clay-coloured, bloody or tarry black poo, ongoing watery diarrhoea, not managing feeds, significant pain or appearing very unwell warrant assessment. Contact your GP or NHS 111 promptly for unexplained blood or unusual stool colour.
Severe drowsiness, difficulty waking, breathing trouble or serious dehydration needs emergency help via 999. Otherwise, consider the pattern over several days.
When to seek support
Some signs need emergency help; other concerns can be discussed with your child’s healthcare team.
- White, grey or clay-coloured poo
- Blood or black tarry poo
- Frequent watery poo, especially with vomiting
- Fewer wet nappies, dry mouth, few tears or unusual drowsiness
- Difficulty feeding, waking or breathing
Sources used for this guide
- American Academy of Pediatrics / HealthyChildren.org — https://www.healthychildren.org/English/healthy-living/nutrition/Pages/when-to-introduce-egg-peanut-butter-and-other-common-food-allergens-to-your-baby-food-allergy-prevention-tips.aspx
- American Academy of Pediatrics / HealthyChildren.org — Baby's First Days: Bowel Movements & Urination
- American Academy of Pediatrics / HealthyChildren.org — The Many Colors of Baby Poop
- American Academy of Pediatrics — Stools - Unusual Color
- NHS — Diarrhoea and vomiting
- NHS — Dehydration
- American Academy of Pediatrics / HealthyChildren.org — HealthyChildren – Teething Pain Relief
English editorial review:
The English text and regional guidance have been checked editorially. This is not an individual clinical assessment.
Luluna provides general parenting information. It does not diagnose conditions or replace your child’s healthcare professional.
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