It's normal for babies to have green stools and mucous in the stool
If your baby cries a lot, it is important that you have your baby assessed by your local GP, to rule out a medical condition. This page belongs to collection of short articles and videos in plain language, called When baby cries a lot. Together, these articles and videos will give you a brief and simple summary of the Possums 5-domain approach to the crying baby in the first 16 weeks of life. For comprehensive information on this topic, please go deeper into the Possums programs, or you might consider reading The discontented little baby book. See your GP if you find blood in your baby's stool, as this needs to be assessed and monitored.
Green stools and mucous in the stool are normal for our babies, whether breastfed or formula fed. Sometimes there can be quite a lot of mucous.
But green stools and mucous in the stool aren't signs of worrying inflammation, allergy, lactose overload, gut dysbiosis or gut problems, despite what you might hear, and will not be a cause of your baby's crying.
Frequency and consistency of baby stools often vary in the one baby, too, and this changeability is more pronounced with the introduction of solids. You can find out more if you are worried your baby is unsettled because of gut pain here.
Acknowledgements
I'm grateful to Professor Sophie Havighurst, Ros June, and Caroline Ma at Mindful, The University of Melbourne, for their feedback on the articles and videos in When baby cries a lot in the first few months of life.
Recommended resources
Is your baby unsettled or having trouble sleeping because of gut pain?
Is baby unsettled or having trouble sleeping because of reflux?
Is your baby unsettled or having trouble sleeping because of allergy?
Is your baby unsettled or having trouble sleeping because of lactose?
Selected references
Huysentruyt K, Koppen I, Benninga MA. The Brussels Infant and Toddler Stool Scale: a study on interobserver reliability. Journal of Pediatric Gastroenterology and Nutrition. 2019;68(2):207-213.