This is an English rendering of a Polish public-health reference. The care paths it names (112, night and holiday care NiŚOZ, primary care POZ) are Polish. This is not medical advice.

PL

This is not medical advice Life-threatening emergency (Poland): 112

Home › Fever and symptoms of illness

What does diarrhea look like in a baby, and how is it different from normal stools in a breastfed or formula-fed baby?

Applies to age: 0–12 months

In short

WHO defines diarrhea as 3 or more loose or liquid stools per day (or more frequent bowel movements than usual for that person), but the loose, pasty stools of breastfed babies are not diarrhea. According to the National Health Fund (NFZ), the sign of diarrhea in babies is a change in stool consistency compared with before and more frequent bowel movements. NFZ recommends contacting a doctor as soon as possible if the child is under 2 months old, the diarrhea comes with vomiting, or you suspect signs of dehydration.

Sources: WHO, NFZ i Akademia NFZ, NHS and othersChecked: Report an error

What is normal

Some claims: international norm

  • Diarrhea is defined as passing 3 or more loose or liquid stools per day, or more frequent bowel movements than is normal for that person.
    Source: WHO · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Diarrhoea is defined as the passage of 3 or more loose or liquid stools per day (or more frequent passage than is normal for the individual).

    WHO · open the source · accessed: 2026-10-09 · license [1]

  • Frequent passing of formed stools is not diarrhea, and neither is the passing of loose, pasty stools by breastfed babies.
    Source: WHO · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Frequent passing of formed stools is not diarrhoea, nor is the passing of loose, pasty stools by breastfed babies.

    WHO · open the source · accessed: 2026-10-09 · license [1]

  • Acute diarrhea occurs when the stool consistency changes to semi-liquid or liquid and bowel movements are more frequent than three times a day.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Z ostrą biegunką mamy do czynienia, gdy konsystencja stolca zmienia się na półpłynną lub płynną, a wypróżnienia są częstsze niż trzy razy na dobę.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • Babies fed breast milk usually have stools of a semi-liquid consistency.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Niemowlęta karmione mlekiem matki mają z reguły stolec o półpłynnej konsystencji.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • In babies, a sign of diarrhea is a change in stool consistency compared with before, together with more frequent bowel movements.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Sygnałem świadczącym o biegunce u niemowląt jest zmiana jego konsystencji w porównaniu do dotychczasowej, a także częstsza liczba wypróżnień.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • After the first days of life, the stool of breastfed babies is liquid (runny) and has no smell.
    Source: NHS · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Breastfed babies' poo is runny and doesn't smell.

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • The stool of formula-fed babies is firmer, dark brown and more smelly.
    Source: NHS · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Formula-fed babies' poo is firmer, darker brown and more smelly.

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Newborns who are breastfed may pass stool at every feeding in the first weeks, and after about 6 weeks may not pass stool for several days.
    Source: NHS · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Newborn babies who are breastfed may poo at each feed in the early weeks, then, after about 6 weeks, not have a poo for several days.

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Formula-fed newborns may pass stool up to 5 times a day, and after a few months this may go down to once a day.
    Source: NHS · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Formula-fed babies may poo up to 5 times a day when newborn, but after a few months this can go down to once a day.

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • A baby's stools probably vary from day to day or from week to week.
    Source: NHS · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    From day to day or week to week, your baby's poos will probably vary.

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • In describing rotavirus diarrhea, the Patient Portal (Portal Pacjenta) lists frequent, watery diarrhea with yellow-green stools, usually without blood and mucus.
    Source: Portal Pacjenta – show the quote

    Verbatim quote from the source:

    Polish original

    biegunka – częsta, wodnista, żółtozielone stolce, zwykle bez krwi i śluzu

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

  • Diarrhea in children most often resolves on its own after about 5–7 days.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Biegunka u dzieci najczęściej ustępuje samoistnie po około 5–7 dniach.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

When to worry

Some claims: international norm

  • With diarrhea, it is worth consulting a health care professional, especially when the diarrhea is persistent, there is blood in the stool, or there are signs of dehydration.
    Source: WHO · international norm – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Consulting a health professional, in particular for management of persistent diarrhoea or when there is blood in stool or if there are signs of dehydration.

    WHO · open the source · accessed: 2026-10-09 · license [1]

  • A drop in a child's body weight of more than 10% during diarrhea indicates significant dehydration and most often requires a hospital visit.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Najbardziej niebezpieczny jest spadek masy ciała powyżej 10%, ponieważ świadczy o znaczącym odwodnieniu i najczęściej wymaga wizyty w szpitalu.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • Visible signs of dehydration in a child include, among other things, a reduced amount or frequency of urine, dark urine, a dry mouth and tongue, fast breathing, pale skin and reduced skin elasticity.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    zmniejszona objętość lub częstość wydalanego moczu ciemna barwa moczu suchość jamy ustnej, języka przyspieszony oddech blada skóra spadek elastyczności skóry

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • Rotavirus diarrhea is most severe in babies up to 6 months old, because their bodies quickly become dehydrated.
    Source: Portal Pacjenta – show the quote

    Verbatim quote from the source:

    Polish original

    Najciężej biegunki rotawirusowe przebiegają u niemowląt do 6. miesiąca życia, ponieważ ich organizm ulega szybko odwodnieniu, dlatego konieczna jest w takiej sytuacji hospitalizacja.

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

Worth discussing with a doctor: international norm

  • A definite change in a baby's stools, for example when they become very smelly, very watery or harder, is a sign that it is worth seeing a doctor.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    If you notice a definite change of any kind, such as the poos becoming very smelly, very watery or harder (particularly if there's blood in them), you should talk to your doctor or health visitor.

    NHS · open the source · accessed: 2026-10-09 · license [3]

ER / 112 (Poland)

Some claims: international norm

Immediate medical help needed: international norm

  • Vomiting blood or vomit that looks like coffee grounds calls for immediate medical help.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    vomit blood or have vomit that looks like ground coffee

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • In children, yellow-green or green vomit calls for immediate medical help.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    have yellow-green or green vomit (children)

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • A child who is confused or not responding as usual needs immediate medical help.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    are confused or not responding as usual

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Blue, gray, pale or blotchy skin, lips or tongue (on dark skin this may be easier to see on the palms or feet) calls for immediate medical help.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    have blue, grey, pale or blotchy skin, lips or tongue - on brown or black skin this may be easier to see on the palms of the hands or soles of the feet

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Significant difficulty breathing or many quick, short breaths calls for immediate medical help.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    are having severe difficulty breathing, or taking lots of quick, short breaths

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Sudden, severe abdominal pain calls for immediate medical help.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    have a sudden, severe tummy ache

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Among the situations in which an ambulance should be called (999, the ambulance number in Poland), the Patient Portal lists persistent vomiting, especially with blood mixed in; this is a general list for all patients, not only babies.
    Source: Portal Pacjenta – show the quote

    Verbatim quote from the source:

    Polish original

    uporczywe wymioty zwłaszcza z domieszką krwi

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

    Polish original

    999 – numer alarmowy pogotowia ratunkowego; połączenie odbiera bezpośrednio dyspozytor medyczny.

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

  • Among the situations in which an ambulance should be called (999), the Patient Portal lists sudden severe abdominal pain; this is a general list for all patients, not only babies.
    Source: Portal Pacjenta – show the quote

    Verbatim quote from the source:

    Polish original

    nagły ostry ból brzucha

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

    Polish original

    999 – numer alarmowy pogotowia ratunkowego; połączenie odbiera bezpośrednio dyspozytor medyczny.

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

  • Among the situations in which an ambulance should be called (999), the Patient Portal lists impaired consciousness and increased shortness of breath; this is a general list for all patients, not only babies.
    Source: Portal Pacjenta – show the quote

    Verbatim quote from the source:

    Polish original

    zaburzenia świadomości

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

    Polish original

    nasilona duszność

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

    Polish original

    999 – numer alarmowy pogotowia ratunkowego; połączenie odbiera bezpośrednio dyspozytor medyczny.

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

See a doctor

Some claims: international norm

Urgent medical assessment needed: international norm

  • Concern about a baby under 12 months old with diarrhea or vomiting calls for urgent medical assessment.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    you're worried about a baby under 12 months

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • A child who stops breastfeeding or bottle-feeding during an illness (diarrhea or vomiting) needs urgent medical assessment.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    your child stops breast or bottle feeding while they're ill

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Signs of dehydration in a child under 5 years old, for example fewer wet diapers, call for urgent medical assessment.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    a child under 5 years has signs of dehydration, such as fewer wet nappies

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Continued vomiting and being unable to keep fluids down call for urgent medical assessment.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    you or your child keep being sick and cannot keep fluid down

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Bloody diarrhea or bleeding from the anus calls for urgent medical assessment.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    you or your child have bloody diarrhoea or bleeding from the bottom

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • Diarrhea lasting longer than 7 days or vomiting lasting longer than 2 days calls for urgent medical assessment.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    you or your child have diarrhoea for more than 7 days or vomiting for more than 2 days

    NHS · open the source · accessed: 2026-10-09 · license [3]

  • According to NFZ, contacting a doctor as soon as possible is advised when the child is under 2 months old.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Jak najszybciej skontaktuj się z lekarzem, jeśli:

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

    Polish original

    dziecko ma mniej niż 2 miesiące

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • According to NFZ, contacting a doctor as soon as possible is advised when the diarrhea comes with vomiting.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Jak najszybciej skontaktuj się z lekarzem, jeśli:

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

    Polish original

    biegunce towarzyszą wymioty

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • According to NFZ, contacting a doctor as soon as possible is advised when you suspect signs of dehydration in the child.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Jak najszybciej skontaktuj się z lekarzem, jeśli:

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

    Polish original

    podejrzewasz u dziecka objawy odwodnienia

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • According to NFZ, contacting a doctor as soon as possible is advised when a child with diarrhea has a persistent high body temperature.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Jak najszybciej skontaktuj się z lekarzem, jeśli:

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

    Polish original

    utrzymuje się wysoka temperatura ciała u dziecka

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • If you notice a drop in your child's body weight during diarrhea, NFZ recommends a quick consultation with a doctor, who will assess the other signs of dehydration, order tests and give recommendations.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Jeśli zauważysz jej spadek, szybko skonsultuj się z lekarzem, który oceni pozostałe parametry świadczące o odwodnieniu, wykona badania i przekaże zalecenia.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • According to NFZ, outside the opening hours of a primary care (POZ) clinic, night and holiday care (NiŚOZ) is available, and you can go to a doctor there when vomiting or diarrhea appears, especially in children.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Nocna i świąteczna opieka zdrowotna to pomoc lekarska po godzinach pracy przychodni POZ.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

    Polish original

    pojawią się wymioty lub biegunka (szczególnie u dzieci i seniorów).

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-09 · license [2]

  • According to the Patient Portal, a sick patient who comes to a POZ clinic should get an appointment on the day of the request, and if that is not possible, at a time agreed with the patient.
    Source: Portal Pacjenta – show the quote

    Verbatim quote from the source:

    Polish original

    Jeśli przyjdziesz chory do przychodni, powinieneś uzyskać wizytę w dniu zgłoszenia.

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [4]

    Polish original

    Jeśli to niemożliwe - w terminie uzgodnionym z tobą.

    Portal Pacjenta · open the source · accessed: 2026-10-12 · license [4]

Myths

  • False Myth: “When a baby has diarrhea or vomiting, you have to stop breastfeeding or bottle-feeding for a while”

    Why it is wrong. With diarrhea and vomiting, you should keep breastfeeding or bottle-feeding, and with vomiting, try giving small feeds more often than usual.
    Instead. Breastfeed at the usual frequency.
    Source: NHS, NFZ i Akademia NFZ – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    carry on breast or bottle feeding your baby – if they're being sick, try giving small feeds more often than usual

    NHS · open the source · accessed: 2026-10-12 · license [3]

    Polish original

    Przestrzegaj dotychczasowej częstotliwości karmienia dziecka piersią.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-12 · license [2]

  • False Myth: “With diarrhea, a child needs a special diet: lactose-free, "binding" or very easy to digest”

    Why it is wrong. There is no indication for introducing a lactose-free, binding or very easy-to-digest diet.
    Instead. Older children who eat solid foods can gradually go back to their usual diet once proper hydration is ensured.
    Source: NFZ i Akademia NFZ – show the quote

    Verbatim quote from the source:

    Polish original

    Nie ma wskazań do wprowadzania diety bezlaktozowej, zapierającej czy bardzo lekkostrawnej.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-12 · license [2]

    Polish original

    W przypadku dzieci starszych, przyjmujących pokarmy stałe, po zapewnieniu właściwego nawodnienia, możesz stopniowo wprowadzać dotychczasową dietę.

    NFZ i Akademia NFZ · open the source · accessed: 2026-10-12 · license [2]

  • False Myth: “With diarrhea, a baby's formula has to be diluted to make it weaker”

    Why it is wrong. Baby formula should be prepared at its usual strength, not weaker.
    Instead. Prepare the formula at its usual strength.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    do not make baby formula weaker – use it at its usual strength

    NHS · open the source · accessed: 2026-10-12 · license [3]

international norm “International norm” next to a section heading means its claims come from a non-Polish source, because no Polish source in our registry covers this topic. When this applies to only some of the claims, the foreign ones carry the same label next to their source.

International norm

“International norm” next to a section heading means its claims come from a non-Polish source, because no Polish source in our registry covers this topic. When this applies to only some of the claims, the foreign ones carry the same label next to their source.

Sources

  1. WHO (who.int)
    License: CC BY-NC-SA 3.0 IGO. Source: WHO (who.int). Content summarized and translated by the editors; changed relative to the original. WHO does not endorse this site or its content.
  2. NFZ i Akademia NFZ
    License: Treści NFZ – wykorzystanie ze wskazaniem źródła, bez obrotu komercyjnego. Source: NFZ i Akademia NFZ. Content summarized and translated by the editors; changed relative to the original.
  3. NHS (nhs.uk, Anglia)
    License: Open Government Licence v3.0. Source: NHS (nhs.uk, Anglia). Content summarized and translated by the editors; changed relative to the original. Contains public sector information licensed under the Open Government Licence v3.0. The summary is ours and is not attributed to the NHS.
  4. Portal Pacjenta (pacjent.gov.pl)
    License: CC BY 3.0 PL. Source: Portal Pacjenta (pacjent.gov.pl). Content summarized and translated by the editors; changed relative to the original.

See an error or outdated information? Report an error in this answer. Answer checked against the sources on October 12, 2026.

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