Constipation (with or without perianal rash)

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) (Carroccio & Iacono, 2006) and can start in the first year of life (Clinical Practice Guideline, 2006).

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 (Clinical Practice Guideline, 2006). But it is also perfectly normal for a breastfed infant not to pass a stool for several days (Hyams et al 1995).

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 Infants)	5 - 28

The Brussels Infants and Toddlers Stool Scale (BITSS) is validated as a reliable instrument to assess stools of non-toilet trained children (Huysentruyt et al 2019).

In a recent study BITSS appeared to be more sensitive to detect hard stools and functional constipation than the Bristol Stool Scale (BSS) (Velasco-Benitez CA et al 2021).

Constipation & CMPA

What causes constipation in infants?

In most cases, the cause of infant constipation is functional starting within the first few weeks or months of life (Dehghani SM et al 2012;Tabbers et al., 2014). However, childhood constipation may have several causes e.g., an change in diet, a stressful event (Clinical Practice Guideline, 2006) or milk allergy (Dehghani et al., 2022).

Constipation with or without perianal rash appears to be a non-specific gastrointestinal sign of CMPA in some infants and toddlers (Koletzko 2012). 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 with a cow’s milk free diet (Iacono et al 1998).

When symptoms occur in infants <1 month of age then an underlying disease should be investigated, e.g., Hirschsprung Disease (Tabbers et al., 2014). Severe infant constipation has an organic cause in a minority of children (Baker et al 1999) but some report improvements with the removal of cow’s milk from the diet (Iacono et al 1995;Iacono et al 1998;Dehghani et al., 2022).

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 (Dehghani et al., 2022; Iacono et al 1995;Iacono et al 1998). In one study, the frequency of CMPA was as high as 80% in constipated infants (Dehghani SM et al 2012).

However, when considering the diagnosis of CMPA, it’s important to consider that the majority of infants with CMPA have at least two symptoms affecting at least two different organ systems (Lifschitz C. and Szajewska H 2015; Høst & Halken 1990; Høst et al 1994).

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 (Vandenplas et al 2015;Vandenplas et al 2022).