Blood in Baby Poo: Causes & When to See a GP | Parenting Hub
Small streaks of blood in a baby's nappy are often from a tiny tear or cow's milk allergy. Bigger amounts always need a GP. Here's how to tell.
Seeing blood in your baby's nappy is frightening. Most causes are minor — but every case deserves a check with your GP.
What it can mean
Causes range from very minor to needing urgent care — describe carefully when you call.
- Small streaks of bright red blood on hard poo — often a tiny tear (anal fissure) from constipation
- Streaks of blood with mucus and eczema or reflux — possible cow's milk protein allergy
- Swallowed blood from a cracked nipple while breastfeeding (looks like dark flecks)
- Blood with diarrhoea — possible gut infection
- Large amounts of dark or jelly-like blood — needs emergency assessment
What helps at home
The right step depends on the cause — but never ignore blood in a nappy.
- Photograph the nappy to show your GP
- If constipation is the trigger, soften poos (see our constipation article)
- Keep feeding as usual
- If you're breastfeeding and have cracked nipples, get help with the latch — it can be the source
When to see a doctor
Any blood in a baby's stool deserves a same-day GP review, even if your baby seems well. They may want to examine baby, take a stool sample or arrange tests.
When to seek urgent care
Some patterns need emergency care, not a GP appointment.
When to seek help
- Large amount of fresh blood
- Dark, tarry stools (can be old blood from higher up the gut)
- Redcurrant-jelly poo with severe pain and vomiting
- Baby is pale, floppy, or hard to rouse
- Blood plus repeated vomiting or a swollen tummy
Common questions
Can teething cause blood in poo?
No. Teething doesn't cause blood in stool — always have it checked.
Is it dangerous if it's just a streak?
Often not — small streaks from a tiny tear are common with constipation. But the only way to be sure is to have it reviewed by your GP.