NICE considers fewer than three complete stools per week to be a potential indicator of constipation in children under one year of age (excluding those exclusively breastfed after six weeks of age)¹. The additional diagnostic criteria for constipation in infants and children up to four years of age is two or more of the following for a period of at least four weeks:

• ≥ one episode of incontinence (in toilet trained children)
• excessive stool withholding
• painful/hard bowel movements
• faecal mass in abdomen
• large diameter stools that may block the toilet².

The first stool passed is a black, tarry, sticky substance (meconium). If this is not passed within the first 48 hours of life seek medical advice. Premature infants may take longer.

Four to six days after birth the dark green, loose, mucousy stools change to the typical milk stool³ (yellow, creamy, soft and runny in breastfed infants/ yellow, sticky and often with a seedy appearance in formula-fed infants).

Bowel movement patterns vary between infants, and frequency is affected by diet, fluid intake, age and behaviour. NICE considers less than three complete stools per week a potential indicator of constipation in children under one year of age (excluding those exclusively breastfed after six weeks of age)¹. Generally, in formula-fed infants, if no stool has been passed for four days and it is hard and dry, this is considered constipation. However, it is worth noting that an exclusively breastfed infant can pass up to six stools per day in the first 28 days of life.

Constipation in infants can occur for a number of reasons:

Functional:

• A change of formula milk (stage change or brand change), inadequate fluid intake, transition from liquids to solids (weaning)
• An intercurrent illness with a temperature/ electrolyte imbalance
• A side effect of prescribed/over the counter (OTC) medication (eg: gastro-oesophageal medication, cough mixtures)
• Older infants can voluntarily/involuntarily withhold bowel movements, usually following a painful experience passing a hard stool
• Rarely, lead poisoning/sexual abuse.

Congenital/medical:

• Congenital abnormalities, e.g: anal stenosis (blocked anus) or Hirschsprung’s disease (aganglionic section of bowel) account for less than 2 per cent of cases of infant constipation⁴
• Medical conditions eg: cystic fibrosis, low thyroid function, diabetes and abnormal electrolyte levels.

Initial signs include distress and difficulty passing a hard, dry stool. If the infant is unable to pass the stool by day five, symptoms include abdominal pain (usually central/left-sided in spasms), reduced feeding and grizzly, hard to settle behaviour. If this situation persists, hard little balls of stool join together forming a mass; the edges of the stools can then liquefy causing watery “overflow” diarrhoea accompanied by passing wind with an offensive odour.

Constipated infants may strain, cry, draw the legs toward the abdomen, or arch their backs when having a bowel movement. However, healthy infants under six months of age may show similar signs for 10 to 20 minutes before passing a normal soft stool. This is known as infant dyschezia and will settle once the infant has learnt to coordinate the relaxation of the pelvic muscles and bearing down².

It is important to first establish whether the infant is breastfeeding successfully and gaining adequate weight. Breastfed infants can pass up to 6 stools per day, but parents should not worry if a stool is not passed every day. Infrequent passing of hard, dry stools in exclusively breastfed infants is rare and should be assessed by a healthcare professional.

The wide variety of formula milks available can confuse parents, and healthcare professionals should familiarise themselves with what is available. Choosing one which contains prebiotic oligosaccharides has been shown to increase the growth of friendly bacteria (including bifidobacteria and lactobacilli)^5,6 – an integral part of an infant’s immune system. Prebiotic oligosaccharides have also been shown to decrease the numbers of potentially pathogenic bacteria^5,7 and help soften stools⁶. Stool composition and consistency can change when formulas are switched. It is advisable to continue with a new formula for at least 3 weeks and seek advice from a health visitor if symptoms persist.

Non-medical remedies can help ease constipation. Between birth and three months offer a small amount of cooled, boiled water between feeds. Formula-fed infants should be fed according to manufacturer’s instructions. Clockwise, circular massaging of the infant’s abdomen or stretching their legs in a gentle cycling motion can alleviate abdominal tension. This should be done when the infant is comfortable and relaxed (e.g. in a warm room after a bath). If the infant is straining, place them on their back in a warm room with the nappy off and gently position their knees against their chest to help them push the stool out⁸.

Bathing will ease abdominal pain and changing a soiled nappy as soon as possible will help the infant feel more comfortable⁸.

NICE suggests dietary treatment shouldn’t be used on its own, but in combination with treatments as recommended by a GP. However, switching to a partially hydrolysed formula can help to soften the stools⁹. The change in formula may cause increased wind and/ or loose, greenish stools at first. These effects are harmless and indicate the digestive system is becoming accustomed to the milk.

A GP can prescribe medication if the severity of the symptoms indicate it is necessary¹⁰. Although infant constipation does not usually require a laxative initially, if symptoms persist a small dose of oral lactulose is often prescribed for infants older than one month¹⁰.

Weaning should not commence until the digestive system is sufficiently developed to cope with solids. The Department of Health guidelines state that solids should not be offered before 6 months^11, and other research confirms that weaning should not begin before 4 months¹².

First foods offered can include soft cooked vegetables (potato, carrot, parsnip) or soft fresh fruit (such as pureed apple, peach, banana). A varied diet rich in fruit and vegetables helps to reduce the likelihood of constipation. Health visitors should be aware that medical conditions (e.g. coeliac disease) can present as constipation during the weaning period.

It is vital that medical help is sought if the infant has a swollen abdomen, temperature, blood or mucus in/around the stool, vomits or shows signs of reduced feeding. Health visitors can help by detecting the problem and making an early referral. They should also ensure that infants on laxative treatment are receiving the drug and an adequate supply is available.