Constipation is defined as a delay or difficulty in defecation, lasting two or more weeks.

It is a common problem often experienced by infants and young children and can start in the first year of life.1 During the first week of life, newborns will typically pass an average of 4 stools per day; this number decreases as the infant reaches 12 months.1 It is also perfectly normal for a breastfed infant not to pass stools for several days or more.2

Average frequency of stool passages in infants3,4


Per week

Per month

0 to 3 months



Breast fed

5 – 40


Formula Fed

5 – 28


6 to 12 months
(All infants)

5 – 28



What causes constipation in infants?

In most cases, the cause of infant constipation is functional,5 most commonly due to painful bowel movements resulting in an infant withholding faeces in order to avoid painful defecation. This may be caused by an intercurrent illness, a stressful event, or a change in routine or diet.1 Severe infant constipation rarely has a medical cause and constipation only has an organic cause in a small minority of children.6


Constipation as a symptom of Cow’s Milk Protein Allergy

Chronic constipation in infants has been shown to be related to the ingestion of cow’s milk and a symptom of CMPA.7,8 In some cases, the frequency of CMPA can be as high as 80% in constipated infants.7


The majority of infants affected with CMPA have at least two symptoms affecting at least two different organ systems.9,10 If, in addition to constipation, your patient shows any of the signs and symptoms that can be related to CMPA11 (see below), you can use the CoMiSS® tool12 to score the combination of their symptoms and assess the likelihood of CMPA.

Signs and symptoms related to CMPA11

  • Gastrointestinal/Digestive: Colic, vomiting, reflux, regurgitation, anorexia, diarrhea, constipation
  • Respiratory: Chronic cough, sneezing, wheezing, runny nose
  • Skin: Rash, urticaria, angioedema
  • General: Failure to thrive, anaphylaxis, insomnia, inconsolable crying

How to score this symptom with the CoMiSS® tool

·         The CoMiSS® tool uses the well-established Bristol stool scale13 to evaluate stool consistency

·         Constipation should only be scored if it lasts for at least one week

·         In addition to the stool score, if any of the following signs or symptoms related to CMPA are also present, they should also be given a score using the CoMiSS® tool. These include crying, regurgitation, skin (atopic dermatitis and urticaria) and respiratory symptoms

CoMiSS® awareness tool

The Cow’s Milk-related Symptom Score (CoMiSS)® is a simple, fast and easy-to-use awareness tool designed to help you more easily recognise the signs and symptoms that can be cow’s milk-related in infants and young children.

CoMiSS® awareness tool is available in print and online version
If you suspect your patient is suffering from symptoms that may be suggestive of CMPA, use the CoMiSS® tool to score and assess the likelihood of CMPA.



1.    Clinical Practice Guideline. J Pediatr Gastroenterol Nutr 2006;43(3) e1–13

2.    Hyams JS., et al. Pediatr. 1995;95:50–4

3.    den Hertog., et al. Arch Dis Child Fetal Neonatal Ed. 2012;97:6 F465–70

4.    Fontana M., et al. Acta Paediatr Scand. 1987;78;682–4

5.    Leung A., et al. Am Fam Physician. 1996;54(2):611–8, 627

6.    Baker S., et al. J Pediatr Gastroenterol Nutr. 1999;29(5):612–26

7.    Dehghani SM., et al. Iran J Pediatr. 2012;22(4) 468–74

8.    Iacono G., et al. N Engl J Med. 1989;339:1100–4

9.    Lifschitz C. and Szajewska H. Eur J Pediatr. 2015;174:141–50

10.  HØst A. Pediatr Allergy Immunol. 1994;5:1–36

11.  Koletzko S., et al. J Pediatr Gastroenterol Nutr. 2012;55(2):221–9

12.  Vandenplas Y., et al. Acta Paed. 2015;104:334–39

13.  Lewis S. and Heaton K. Scand J Gastroenterol. 1997;32(9):920–4

IMPORTANT NOTICE: Mothers should be encouraged to continue breastfeeding even when their babies have cow’s milk protein allergy. This usually requires qualified dietary counseling to completely exclude all sources of cow’s milk protein from the mothers’ diet. If a decision to use a special formula intended for infants is taken, it is important to follow the instructions on the label. Unboiled water, unboiled bottles or incorrect dilution can make babies ill. Incorrect storage, handling, preparation and feeding can eventually lead to adverse effects on the health of babies. Formula for special medical purposes intended for infants must be used under medical supervision.