Constipation (with or without perianal rash)

Digestive Symptoms of Cow'S Milk Protein Allergy.

Constipation is defined as a delay or difficulty with defecation, lasting two or more weeks. It is a common problem in infants and young children (with up to 16% affected)1 and can start in the first year of life.2 


During the first week of life, newborn infants will typically pass an average of 4 stools per day; this number decreases as the infant reaches 12 months of age.2 But it is also perfectly normal for a breastfed infant not to pass a stool for several days.3


 Average frequency of bowel movements in formula and in breastfed infants (den Hertog et al 2012: Fontana et al 1987)
 Age Per Week
 0 - 3 Months 
 Breastfed 5 - 40
 Formula Fed 5 - 28
6 to 12 months 

 All Infants5 - 28


The Brussels Infants and Toddlers Stool Scale (BITSS) is validated as a reliable instrument to assess stools of non-toilet trained children.6 

In a recent study BITSS appeared to be more sensitive to detect hard stools and functional constipation than the Bristol Stool Scale (BSS).7

What Causes
Constipation in

In most cases, the cause of infant constipation is functional starting within the first few weeks or months of life.8,9 However, childhood constipation may have several causes e.g., change in diet, a stressful event2 or milk allergy.8 Constipation with or without perianal rash appears to be a non-specific gastrointestinal sign of CMPA in some infants and toddlers.10

In one study they reported intolerance to cow’s milk was the cause of severe perianal lesions with pain on defecation and constipation, resolving rapidly on a cow’s milk exclusion diet.11

When symptoms occur in infants <1 month of age then an underlying disease should be investigated, e.g., Hirschsprung Disease.9 Severe infant constipation has an organic cause in a minority of children12 but some report improvements with the removal of cow’s milk from the diet.8,11,13

Could It Be a
Symptom of
Cow’s Milk
Protein Allergy?

Chronic constipation in infants appears to be associated with the ingestion of cow’s milk and CMPA, while the removal of milk and dairy has been shown to improve constipation.8,11,13 In one study, the frequency of CMPA was as high as 80% in constipated infants.8

However, when considering the diagnosis of CMPA, it’s important to understand that the majority of these infants have at least two symptoms affecting at least two different organ systems.14-16

Therefore, it is important to consider the individual child as well as the magnitude of their symptoms. This can be achieved using an awareness tool such as the Cow’s Milk Related Symptom Score (CoMiSS™) which will help you determine if CMPA might be indicated.17,18

Overview of Symptoms

Respiratory icon


Up to 30% of affected infants with CMPA have respiratory symptoms15,20

Anaphylaxis icon


Anaphylactic shock is a severe, immediate, allergic reaction, which can affect many organ/systems

Skin icon


Up to 75% of infants with CMPA can have skin-related symptoms21

General Symptoms icon


Inconsolable crying is very common in infants with CMPA associated with sleeping problems and food refusal