The pharmacy-trained guide to baby stool colours — from meconium black to breast milk yellow, from concerning white to alarming red — and exactly when each colour requires urgent medical attention.
The baby poop colour chart exists for one reason — because parents panic when they see green stool, orange stool, or seedy yellow stool and have no idea what any of it means. Most of it is completely normal. Two colours require urgent medical attention. This guide tells you which is which.
Black (meconium): Days 1–3 of life. Thick, tarry, dark green-black. Completely normal. Transitions to yellow-green by days 3–5. If your baby has not passed meconium within 24 hours of birth, tell your midwife.
Mustard yellow: The classic breastfed baby stool. Soft, loose, seedy. Can happen 8–10 times per day in a newborn. Completely normal.
Dark green: Common in breastfed babies. Also seen after iron supplements. Often indicates more foremilk than hindmilk — try longer feeds on one breast first.
Orange and brown variations: Normal. Colour changes with diet, particularly during weaning. Firmer consistency is normal once solids are established.
Pale, chalky white, or grey — contact your GP within 24 hours. This is the most important colour in this guide. Pale stools can indicate biliary atresia — a serious but treatable liver condition. Outcomes are significantly better when caught early. Do not wait.
Red or blood-tinged — contact your GP same day. Possible causes include a small anal fissure, cow's milk protein allergy, or infection. If you are unsure whether it is blood or food — call your GP.
Black after the meconium phase — contact your GP today. Can indicate upper gastrointestinal bleeding. Exception: iron supplements cause dark or black stools. If not on iron: call your GP today.
In a baby under 1 year, diarrhoea not improved after 24 hours warrants a call to your GP or NHS 111. In children over 1 year, seek advice if it lasts more than 7 days. Watch for dehydration signs alongside diarrhoea: fewer wet nappies, no tears when crying, dry mouth, sunken fontanelle.
NHS newborn bowel movement guidance · GOSH stool colour guidance · Biliary Atresia UK (BAUK) · NICE · Reviewed April 2026.