All content of this blog is my own opinion only. It does not represent the views of any organisation or association I may work for, or be associated with. Nothing within this blog should be considered as medical advice and you should always consult your Doctor.

Green nappies - what do they mean when breastfeeding?

Green nappies - perhaps one of the most talked about subjects on a lot of breastfeeding forums.  "What do they mean? Is everything ok? What should I do?!".  I've certainly seen some interesting replies, with one popular site suggesting "green stools are a warning!" ooh heck!

There are several reasons for stools veering from the typical yellow/mustard/seedy/curdy breastfed type - like most things there isn't a one answer fits all reply; we need to look at the whole picture.

Firstly if baby is happy, content, gaining weight well and the only issue is stools are green - I think it's Dr Newman who suggests popping on some sunglasses.  Secondly sometimes stools can go green for a day or two due to a bug, teething, medication mum is taking (such as antibiotics or iron supplements), a random food mum ate, supplement (such as spirulina) or just because!  if all else is well, green nappies alone mean very little.

Green poo can also occur because baby isn't getting enough fat, or enough in relation to the lactose rich milk at the start of a feed (often called foremilk).  Lactose moves through the system very quickly - without fat to slow the process the baby can't produce lactase (to process the lactose) fast enough.  In response bile is produced which is what gives the stool it's green colour.

The common answer to this is often to block feed, or stick to one side - and in some cases (ie if oversupply is the reason), this will help.  But it isn't the only cause, and so suggesting a technique designed to reduce supply without being sure can be risky.

It could be that baby isn't milking the breast as effectively as they could - perhaps due to tongue tie or positioning/latch that needs a tweak.  If so it can be hard for them to release the fat and in some cases they will tire before they reach it (rather like if we half squish a straw and then attempt to drink) - what happens next depends on the baby and their age.  Some will "power feed", drinking the letdown, pulling off and then repeating an hour (or less) later, some will do this on both sides ie taking the top off each and accessing the fattier milk in neither.  Younger babies often fall asleep quickly at the breast, ie after the letdown - baby may be called "lazy" or a "snacker" but in reality once the milk becomes hard/impossible to reach, a small baby will sleep!

I think what confuses people is that baby falling asleep on the breast is a sign they have "finished" with it and so swap them over.  However, this is when baby falls asleep after actively feeding well on the breast - if a baby is falling asleep because they are not well attached and thus feeding is tiring, they are likely to fall asleep long before they empty the breast!  Watching for active milk transfer not just how well baby appears to be latched is key.

Babies in this group may have lower than expected weight gain and if baby isn't taking sufficient milk, stools may appear dark green/brown and may be small/less frequent than expected.  Others will gain weight very well, due to the regular calorific foremilk hit!  Maximising milk intake by ensuring effective feeding, breast compression & switch nursing can help, further information here.

Another cause can be swapping sides before baby has finished the breast - most often because mum has been told to feed for a set number of minutes. This article explains why.

Antibiotics can cause a windy/fussy green stooling infant which is also worth noting if they begin around the same time as the medication.  A virus can also cause a short term change to stools.

As mentioned green poop can also be down to a large supply, ie mum is becoming extremely full and engorged before each feed (typically once supply would normally have established and level out) baby can sometimes feel satiated before they  get to the fattier milk. Mums usually know if they have a large supply - they may frequently feel engorged (beyond the typical physiological engorgement when milk "comes in") and hard between feeds. Oversupply is most common when baby is around 3 weeks old onwards.

NB - choking/spluttering/pulling back when feeding is often described as a sign of oversupply/fast letdown.  However if baby has a disorganised suck for some reason, and cannot effectively co-ordinate feeding - he will do the above even when the flow is a perfectly normal speed.

Allergy or intolerance to something in mums diet can occasionally be a cause - dairy is the most common culprit (it is thought mum only passes milk protein via breastmilk if she herself is intolerant perhaps without knowing, or has something else causing a "leaky gut") these stools are often described as stringy/mucousy or flecked with red/black.  However mucous indicates irritation of the intestinal lining and so can also be caused by a cold, virus or teething and often passes in a day or two.  In very rare cases bowel movements filled with mucus like jelly streaked with blood, often compared to currant jelly (usually accompanied by abdominal cramps and vomiting) can be caused by a bowel blockage called Intussusception - always consult your doctor immediately if you are all concerned about the health of your baby.

Babies born by Cesarean section are at increased risk of a disturbed gut flora and thus "nappy issues" due to lack of bacterial colonisation via the birth canal, as are infants whose mothers had antibiotics shortly before, during or after labour (or during the duration of breastfeeding), or who have food sensitivities (recognised or undiagnosed) .  Many experts now recommend probiotic supplements for higher risk infants.

Is it Diarrhoea? 

Exclusively breastfed infants will pass poo that is fairly runny as standard; diarrhoea differs in that it is far more watery and mucus-like in consistency. It may leave more of a water stain than a stool as the liquid is absorbed into the nappy.  There is a risk of dehydration if your baby is being sick as well as suffering from diarrhoea, and/or if it accompanied by a fever or sweating - if you have any concerns always consult your doctor.


  1. This comment has been removed by the author.

  2. Awesome post, I want to check out a couple of your other messages. Thank you!

  3. This is the perfect web site for everyone who wishes to understand this topic. You know so much its almost tough to argue with you (not that I really will need to…HaHa). You certainly put a fresh spin on a subject which has been written about for a long time. Wonderful stuff, just excellent! breast enlargement london

  4. My baby is 6 weeks old and has been exhibiting green stools for around 2 weeks with the occasional return to mustard stools. The HV has been unable to suggest a treatment and doctor isn't interested unless stools are red, black or white.
    I was interested by your comment about babies born by c sec with mum on antibiotics following birth. This was the case for my delivery and, had I known of the health implications of antib's on baby's immune system and sensitivity to allergens I would have refused the drugs. You mention probiotics as a possible remedy; with the lack of healthcare support I've received so far I was wondering if you could give me advice on what to get and where? I have given up dairy and changed my feeding technique to no avail, last thing I want is to formula feed if I can avoid it.

    Thanks in advance and great site, very informative and finally found someone that seems to know what they're talking about!

    1. Hi Gillian, drop me a line - title of blog :)

    2. Antibiotics are necessary after c-section, post-op infection would be disastrous.
      C-section babies have underdeveloped gut biota even if mum doesn't take antibiotics. Try taking probiotics to help out baby. If baby is old enough probiotic powder in bottle/food.

  5. Hi thanks for this post its really informative. I have a little boy who is 14 weeks and has had bright seaweed green watery nappies for over 2 weeks, nearly 3. I'm not on any meds, eat very little dairy (no milk occasional cheese) and have a good diet that hasn't altered. I had a night out last month but otherwise don't smoke or drink even on a weekend. He feeds fully from each side before swapping as far as I can tell, and nothing has changed in his feeding pattern either. Took him to doctor who checked him over and said she wasn't worried as no tummy pain, he is alert and feeds well & has regular wet nappies. But I'm not happy and I don't know why his nappies would suddenly change like that. He was an emergency c-sec & we were both given antibiotics after delivery (though our bloods came back fine) so on advice of Midwives we both took probiotics for about the first 6 weeks.

    Wonder if you had any thoughts as to what may be the cause of this sudden change? He seems absolutely fine but something must be going on. Appreciate your advice

    1. AMANDA WHITAKER^^ Did you find out what the culprit was? My baby is the exact same at the moment and I am very confused about what to do

    2. Same here. Any idea what caused it?

    3. I'm having the exact same thing!!

    4. I'm having the exact same thing!!

  6. Thank you so much for this valuable information. I now have a better understanding of what is going on with me and my baby.

  7. My little girl is 8 weeks old and for the last 2 weeks or so has had green stools. She had her first lot of immunisations and wondering if that is linked. I also got told she may have a slight posterior tongue tie but the doctor doesn't seem to think so. She was also born by c-section and 2 weeks in I got bas mastitis and was on anti biotic. She seems to get alot of wind so is on wind drops currently. There are a few things the green poo could be linked to.