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Why is the newborn's feces green with mucus, lumps and what to do?
Last reviewed: 05.07.2025
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A change in the color of a child's stool can cause concern in young, inexperienced parents. Sometimes it is justified, but in general a greenish tint of a baby's stool is quite acceptable and does not in itself convey information about the child's illness.
The first bowel movements of a newborn are very dark, almost black in color with a greenish tint (meconium), have a texture reminiscent of viscous putty, which is replaced by lumpy poop of a yellow color with greenish streaks of meconium residue. Later, after about a week, mustard-colored feces are found in the baby's diaper, it is also called the color of a baby's surprise, the texture of which resembles liquid puree. If the contents of the diaper turn out to be an unusual color, parents may panic, although in the vast majority of cases there are no reasons for this. Usually, the infant's body reacts to the intake of certain substances by changing the color of feces.
Causes green feces in a newborn
The color of feces is individual and is determined by the newborn’s diet and the degree of “maturity” of its digestive organs.
The stool of babies who are fed with adapted formulas from the first days of life, as a rule, does not differ in color variety. The appearance of greenish feces in a formula-fed baby can be caused by new baby food, in particular, with an increased iron content.
Breastfed babies have more harmless options for green stool:
- mother's diet, including lots of green vegetables (cucumbers, salads, zucchini);
- vitamin complexes that a nursing woman can take (they almost always contain iron);
- oxidation of the contents of a diaper that was not removed in time;
- insufficient intake of so-called “hind” milk by the child.
Regarding the last point, risk factors for not receiving the fattier and more nutritious milk produced at the end of feeding are the following: the mother limits the time of sucking and/or frequently changes breasts (more often than every two hours).
Malnutrition, which is manifested by the presence of green in the stool, can also be caused by a small amount of milk in the mother. Risk factors for malnutrition are anatomical features of the nipples (inverted or flat), tight breasts (especially in primiparous women).
A greenish tint to a child's stool may appear almost immediately, especially if the child is breastfed, since the microflora of mother's milk contains various bacteria, and the child's sterile intestines after birth must adapt to it. Artificially fed babies also adapt, and both the mother and the child may have been prescribed antibacterial drugs, which is also a cause of dysbiosis in the infant's intestines.
Hypoxia during childbirth can cause inflammation of the mucous membrane of the digestive tract, and even if the mother has rivers of milk, her child’s feces will look like transitional ones for a long time (with a pronounced green tint).
Immaturity of the liver enzyme systems leads to the appearance of a greenish tint in children's feces; this condition, like intestinal imbalance of microorganisms, usually goes away without treatment.
The reason for a change in the color of feces in older infants (after six months) is often the introduction of complementary foods. This applies to all categories of infants - both formula-fed and breastfed.
However, if the stool is always green and there are other symptoms, the child should be examined to rule out or confirm congenital enzyme deficiency or bacterial infection of the newborn. The first of the reasons - true lactose intolerance, as well as galactosemia - are quite rare pathologies and manifest themselves early, in the first days of life with quite pronounced symptoms. Transient lactose intolerance, which is much more common, goes away on its own as the child's digestive process improves. The main contingent of the risk group is premature babies, whose small intestinal mucosa is underdeveloped. Transient lactase deficiency can also be caused by gastroenteritis, an allergic reaction to cow's milk protein, or celiac disease (gluten intolerance).
Pathogenesis
It is possible to talk about a pathological mechanism of change in the color of a newborn's stool only if there is a pathology. Harmless reasons for the appearance of green feces, such as: the diet of a nursing mother, oxidation in the air - are not pathologies. The consequences of taking antibiotics cause minor disturbances in the intestinal microflora, but when the drugs are discontinued, they disappear. An unsettled balance of microorganisms in the intestine or enzyme activity also quickly returns to normal.
Lactase deficiency (lactose intolerance) deserves special attention. True (primary) lactose intolerance, a fairly rare metabolic disorder, is hereditary. In this case, the mechanism of this pathology is due to low enzymatic activity of lactase or its complete absence, while the cells of the digestive tract enterocytes, which should synthesize this enzyme, remain undamaged.
The same mechanism is inherent in the development of transient (temporary) lactose breakdown disorder. Premature and full-term but immature newborns have insufficiently high enzymatic activity of lactase. As a result, most of the lactose remains undigested, beneficial lactic acid bacteria (lactobacilli, bifidobacteria, lactose-positive intestinal bacteria) cannot cope with its breakdown, which causes noticeable symptoms, including greenish color of feces. They turn green as a result of too fast movement of food through the digestive tract - the faster the digestive cycle, the more intense the green color of the feces. Dysbacteriosis caused by a bacterial infection, taking medications, is also due to an imbalance of the baby's intestinal biocenosis in favor of pathogenic and opportunistic microorganisms.
An inflammatory process in the intestine of any nature causes damage to enterocytes and, as a consequence, secondary lactase deficiency. At the same time, inflammations of allergic genesis are quite common, especially in formula-fed babies, who encounter foreign proteins from soy or cow's milk too early, which are the basis of adapted mixtures. When they enter the child's intestines, immunocytes identify them as "foreigners", and the response to this is an allergic inflammatory reaction.
If a child receives only breast milk, then allergic inflammation in him can be caused by allergenic foods in the mother’s diet.
[ Symptoms green feces in a newborn
So, the concept of a standard for the appearance of feces of a newborn is somewhat vague, especially for children who are breastfed. Theoretically, a greenish color, lumps and inclusions, a little mucus found in feces are not yet symptoms of ill health. Basically, attention should be paid to the condition and behavior of the child. If the baby does not suffer from lack of appetite, sleeps peacefully, gains weight well, then there is no need to worry. The decisive factor for parents should not be so much the shade of feces, but the behavior and mood of their baby.
Yellow stool with green lumps in a newborn is not a symptom of a disease, it is a variant of normal feces. However, the appearance of the stool can indicate many things.
Thus, green feces in a breastfed newborn, watery, foamy and quite frequent, are often called "hungry". It indicates that the mother often changes breasts during feeding, and the child mainly feeds on low-fat milk, and thick, nutritious and fatty milk simply does not reach him. Additional signs of this state of affairs are - insufficient weight gain per week, frequent hungry crying of the child.
Yellow-green feces in a newborn can be a sign of allergic inflammation if the color is accompanied by frequent (more than 10 times a day) bowel movements with mucus. If nothing else bothers the baby, then this condition can be considered a normal variant.
Dark green feces in a newborn, resinous, viscous, almost black, are observed in the first days after birth. It is replaced by a greenish transitional one, which may contain streaks of meconium. In older infants fed with breast milk, a fairly dark green feces can be caused by the intake of activated carbon by the nursing mother. Preparations containing iron and dyes can also change the color range of children's feces.
In short, if a breastfed newborn has stool with green lumps, a small amount of mucus or foam, and no other symptoms, it can be considered not worthy of particular concern.
Green feces in a newborn on artificial feeding as a normal phenomenon may appear when changing the brand of baby food. In general, in children who are fed with adapted mixtures, feces have a more formed appearance and a constant color. In artificially fed babies, green in the feces may be a sign of food allergies or inflammatory processes of the intestinal mucosa, a complication of which is secondary lactase deficiency and / or a violation of the intestinal microflora.
It happens that when there is insufficient breast milk, the child is supplemented with adapted formulas. Green feces in a newborn on mixed feeding in this case can be caused by both the peculiarities of the mother's diet and the reasons typical for formula-fed children.
Alarming symptoms that accompany green stool include bloating, colic, rash, frequent regurgitation or vomiting, unusual weakness and lethargy of the baby, more frequent or, conversely, less frequent than usual bowel movements with a sharp unpleasant odor, persistent diaper rash caused by loose watery stools and, of course, bloody streaks in the feces and an increase in body temperature.
The first signs to pay attention to are when the baby, who is actively starting to suck, suddenly stops doing it, cries, arching, or pulling his legs up to his tummy. At the same time, the baby's feces are liquid, greenish, foamy, and smell sour. Such symptoms allow us to suspect a deficiency of lactase activity.
Primary (congenital) deficiency is characterized by an increase in symptoms as the consumption of mother's milk increases. At first, these are periodic colic and flatulence, later - regular abdominal pain, then - stool disorders. Congenital lactase deficiency is worth thinking about if there is lactose intolerance in the family of close adult relatives, since the disease is hereditary.
Lactose intolerance can be confused with a rare congenital metabolic disease caused by the absence or low activity of the enzyme that catalyzes the process of breaking down galactose into glucose - galactosemia. Symptoms in this case appear from the first days and are manifested by jaundice, vomiting, hepatomegaly, refusal to breastfeed, neurological manifestations. A distinctive feature is that with lactose intolerance, vomiting is not observed, only frequent regurgitation.
Secondary lactase deficiency often develops against the background of inflammatory processes in the intestines of a newborn of any genesis. In this case, various types of green stools may be observed, an abundance of mucus, diarrhea are typical. Green mucus may be observed in the feces of a newborn. Inflammatory processes are usually accompanied by fever, vomiting, indigestion, dehydration. Allergic inflammations often begin with diarrhea and vomiting, skin manifestations may be absent for a long time. Symptoms of hypersensitivity resemble signs of lactose intolerance, while in addition to green foamy and liquid stool, streaks of blood may also be observed in the feces. In this case, specialist help is needed.
Complications and consequences
In the vast majority of cases, green feces in a newborn is a normal variant and, if the child’s behavior indicates that he is comfortable, then it does not entail any negative consequences.
Moreover, close attention of parents and excessive vigilance of the local pediatrician can lead to unnecessary treatment and transfer of the child to artificial feeding. Lactose deficiency and dysbacteriosis have now become quite popular and often unfounded diagnoses, which is facilitated by the widespread advertising of lactose-free mixtures. True intolerance to mother's milk is extremely rare and is accompanied from the first days of life by pronounced symptoms that are difficult to miss. Incomplete breakdown of lactose in healthy newborns, which is often mistaken for lactose deficiency, is an absolutely normal phenomenon often up to five months of age. And if a small child is deprived of lactose from the first month of life, then lactic acid (beneficial) bacteria will not be able to develop in the intestines in sufficient quantities and their place will be taken by pathogenic microorganisms. In this case, the situation will become significantly more complicated.
However, parents should not relax completely, the child's condition must be monitored so as not to miss really serious pathologies. Congenital enzymatic disorders really require special nutrition for the child. Inflammation of the intestinal mucosa caused by infection or food allergy also requires specialist intervention. Gastroenteritis in a newborn is usually acute, dehydration of the body occurs quickly, so emergency measures must be taken to prevent further development of the disease, complications and even death of the baby.
Diagnostics green feces in a newborn
You should contact a doctor with complaints about green in your baby's stool if this circumstance is accompanied by any of the following symptoms: diarrhea (meaning twelve or more soiled diapers per day, foamy watery stools with a sharp unpleasant odor), vomiting or very frequent regurgitation, poor appetite, lethargy, high temperature, underweight or weight loss, signs of dehydration.
The child will be prescribed a stool test for sugar, which allows to assume how completely carbohydrates are digested and absorbed in the intestine, a stool test for coprogram and intestinal microflora. A breath test for hydrogen, a clinical blood test, which excludes or confirms the presence of inflammation, and a breast milk test for pathogenic microorganisms may be prescribed.
Based on the examination data and test results, differential diagnostics are usually carried out by the exclusion method: congenital metabolic disorders are excluded, lactose intolerance and dysbacteriosis, which, by the way, are often combined with each other, are differentiated, the etiology of the inflammatory process is determined, and so on.
Who to contact?
Treatment green feces in a newborn
If, apart from the color of the feces, nothing else bothers you, then you need to continue breastfeeding your baby, having analyzed your diet, excluding synthetic additives, dyes, limiting the amount of vegetables and fruits, and also - possible intake of medications, including vitamins. With a change in the mother's eating style and cessation of medication, the color of the stool usually normalizes. It should be taken into account that a greenish tint of feces can be observed in the baby for quite a long time, up to three to five months, stabilization of the intestinal microflora is an individual process and can also be lengthy.
What to do if a newborn has green stool?
If a newborn cries often, sleeps restlessly, and can't stand even an hour or an hour and a half between feedings, it can be assumed that he is not getting enough to eat. If this continues for several days, you may notice a lack of weight gain, a decrease in the amount of urine excreted, and a decrease in the quality of urine (more concentrated, with a strong odor). In this case, the number of feedings is increased - the baby is put to the breast at the first request, at any time of the day, the sucking time is not limited, feeding from both breasts in one feeding, and nipple shields are used if their shape is inconvenient. Usually, you can establish breastfeeding on your own, adapting to the requirements of your baby, flexibly combining them with your needs. There are now enough recommendations on breastfeeding published. In extreme cases, you can seek advice from a specialist.
If the most common and harmless causes have been eliminated, and the stool still remains greenish, but the baby's behavior indicates that he is comfortable, you can not worry. Most likely, his intestinal microflora has not yet returned to normal or the color of the feces is a consequence of slight oxygen starvation during labor. After all, even in absolutely healthy and full-term babies, transitional stool can be observed for up to three months or more. This is very individual, and it is better not to interfere with the development process if there are no symptoms of delay. The best means for the normal functioning of the newborn's body, its maturation and formation is mother's milk.
In case of prolonged manifestations of symptoms of intestinal microflora disorder, it is recommended to do a bacterial culture of mother's milk. If pathogenic microorganisms are found in it, the mother is treated - antibiotics are prescribed, and at this point breastfeeding is stopped. However, it is still better to restore it later.
In case of pronounced painful symptoms, not limited only to the color of feces, you should contact a pediatrician and undergo an examination. Depending on its results, the baby will be prescribed treatment.
Prevention
The best form of nutrition for the growth and development of a newborn, as well as the prevention of dysbacteriosis, allergic inflammation, intestinal and other infections is breastfeeding, and the most effective prevention is high-quality breast milk.
Currently, many recommendations have been developed for establishing breastfeeding, using which you can find your own feeding scheme that is convenient for both mother and child. Feeding on demand promotes better lactation, saturation, growth and development of the child.
For a formula-fed baby, you need to choose the right formula and try not to change it often. When changing the formula, it takes at least a week for the baby's body to adapt to the new nutritional composition.