Constipation and diarrhoea

It can be difficult to know what’s ‘normal’ when it comes to an infant’s bowel movements. The frequency and consistency of stools can vary, but symptoms of constipation and diarrhoea are easy to spot


Like adults, babies and infants are all different in terms of how often they normally pass stools – for some, it will be a few times a day, whereas others will only go a few times a week. Parents may ask you for advice if their baby hasn’t passed stools as often as normal.


The criteria used to diagnose constipation in infants up to four years of age is that two of the following symptoms must be present for one month:

  • Two or fewer defaecations per week
  • History of exessive stool retention
  • History of painful or hard bowel movements
  • Presence of large faecal mass in the rectum
  • History of large stools, which may obstruct the toilet.

Accompanying symptoms may include being irritable and unhappy, loss of appetite, tiredness, excessive flatulence, foul smelling wind and stools, and abdominal discomfort and pain. These symptoms may disappear after a bowel movement.


Constipation is common among babies and infants, although it doesn’t usually occur in babies who are exclusively breastfed. The cause of the problem can vary, and may include:

  • Diet and dehydration, if lacking in fluid, fruit or vegetables
  • Toilet training
  • Emotional causes (e.g. starting nursery or a new sibling arriving)
  • Medication side effects
  • Not being very active.


If a baby has constipation and has not yet been weaned onto solid foods, the first course of action is to give them cooled, boiled water between their normal milk feeds. Advise parents to continue making up formula milk as usual – it should never be diluted or over-concentrated. You can also suggest that parents gently massage their baby’s abdomen or move their legs in a clockwise, ‘cycling’ action to help stimulate their bowels.

For babies who have already been weaned, recommend that parents give them plenty of water (a small amount of diluted fruit juice can also be given to infants over 12 months) to drink and include more fruit and vegetables in their diet. Fruits that are good for constipation include apples, pears, peaches, apricots, prunes, grapes, raspberries and strawberries. Toddlers who experience constipation should be given regular, frequent meals and should try to stay active. Parents should also encourage good toilet habits to teach the child to go when they feel they need to.

If the problem hasn’t improved after trying any of the above suggestions, you should refer parents to a pharmacist or a GP, as the infant may need an osmotic or stimulant laxative (e.g. lactulose or senna).

Clinical summary:

Early diagnosis and management of constipation is important in order to prevent it causing complications, such as a painful anal fissure or embarrassing continence issues such as soiling, or becoming chronic. Additional obstacles exist in the form of a reluctance to seek advice in the first place because of embarrassment, and the conflicting information that many people receive. Both can impact on the effectiveness of treatments and lead to a great deal of frustration.

In its clinical guidance on the topic, NICE states that a full assessment should be conducted before constipation is diagnosed. Underlying causes and red flag symptoms, such as abdominal distension with vomiting which could indicate intestinal obstruction, should be excluded at this time.

First-line treatment for impaction is with an oral macrogol (polyethylene glycol 3350 plus electrolytes). If this product isn’t tolerated, a stimulant laxative (sodium picosulfate, senna or docusate sodium) may be given either on its own or with the osmotic laxative lactulose. All infants should be reviewed within a week, and rectal medication is only recommended if oral treatments fail.

If the infant doesn’t have faecal impaction, or once it has been relieved, maintenance therapy should be started (under the advice of a doctor). First-line treatment is with a macrogol, the dose adjusted according to symptoms and response. A stimulant agent may be added or substituted if the macrogol does not work or is not tolerated. The regimen should be followed for several weeks after regular bowel habits are restored, which may take several months. Frequent reassessments should be conducted, ideally by the same healthcare professional, in order to ensure that re-impaction has not occurred and to provide advice on any other issues. Medication should not be stopped abruptly, but instead gradually reduced over a period of months while keeping an eye on stool consistency and frequency. Therapy may be required for several years or on an ongoing basis.

Information on diet and lifestyle interventions should be provided, but are not considered first line treatments on their own.

It is quite normal to see some variation in the consistency of a baby’s stools, but if there is a sudden change in consistency to loose or watery stools, it is classed as diarrhoea.


It is quite normal to see some variation in the consistency of a baby’s stools, but if there is a sudden change in consistency to loose or watery stools, it is classed as diarrhoea


As well as loose, watery stools, associated symptoms may include:

• Stomach cramps
• Nausea and vomiting
• Headache
• Loss of appetite
• Dehydration.

If diarrhoea lasts longer than 48 hours in babies aged between three months and one year, or if a baby passes six or more diarrhoeal stools in 24 hours, refer parents to a pharmacist/GP.


A common cause of diarrhoea is a viral or bacterial infection. This is normally self-limiting and will clear up on its own within a couple of days. It may also be a sign that the baby is having difficulty digesting lactose or has an allergy to cows’ milk protein.


Parents should continue to offer the same feeds as usual. Older babies should be offered frequent sips of water. If babies don’t want to eat, drinks should still be offered regularly to prevent dehydration. An overthe- counter oral rehydration solution may also be suitable.

Babies are at high risk of dehydration, so parents should monitor them closely if they have diarrhoea or sickness. Signs of dehydration include drowsiness, passing little urine, glazed eyes, and a dry mouth or tongue. If babies show any of these signs, they should see a doctor immediately.

Clinical summary:

The most common cause of diarrhoea in infants is gastroenteritis – mostly viral in origin, but sometimes caused by a bacterial or protozoal infection – and is usually self-limiting. According to NICE, red flag symptoms, i.e. those that indicate a diagnosis other than gastroenteritis, include:

  • Fever (38ºC or higher in babies under three months of age, or 39ºC in infants older than this)
  • Shortness of breath
  • Altered consciousness
  • Neck stiffness
  • Bulging fontanelle
  • Non-blanching rash
  • Blood or mucus in stools
  • Bilious vomit
  • Severe or localised abdominal pain and abdominal distension or rebound tenderness.

During assessment, healthcare professionals should be alert to the signs of dehydration – altered responsiveness, decreased urine output, sunken eyes, tachycardia, tachypnoea, reduced skin turgor and general malaise – and clinical shock, which may manifest as decreased level of consciousness, pale or mottled skin, cold extremities and weak peripheral pulses. These are more common in infants aged under one year (and particularly those younger than six months), babies who were of low birthweight, and individuals who have had more than five diarrhoeal stools or two bouts of vomiting in the previous 24 hours or who cannot tolerate fluids (including breast milk).

In most cases, the main aim of treatment is to prevent dehydration by continuing breastfeeding and other milk feeds, encouraging fluid intake (though not fruit juice or carbonated drinks) and offering oral rehydration therapy (ORT). The latter should be used in all individuals who show signs of dehydration, ideally frequently and in small amounts.

Intravenous fluids may be indicated if clinical shock is suspected, and for children who cannot tolerate ORT or who continue to deteriorate despite taking it. If the child is on solid foods, these should be stopped while ORT is being given, but reintroduced immediately once the child has become rehydrated. Antidarrhoeal medicines, such as loperamide are not recommended, and antibiotics should not be given routinely.

Most children who have gastroenteritis can be safely managed at home, with advice and support from a healthcare professional on the need for scrupulous handwashing and other hygiene practices, awareness of the signs of dehydration and when to seek medical help.


Top tips for constipation & diarrhoea

  • The best way to avoid constipation is to make sure that an infant eats plenty of fibre. Fruit, which can be chopped or puréed depending on the baby’s ability to chew, is a suitable option. The best fruits for managing constipation are apples, apricots, grapes, peaches, pears, plums, prunes, raspberries and strawberries
  • If a baby has diarrhoea, it is important that everyone in the family washes their hands regularly with soap and warm water to avoid spreading the infection.


Next, read the article on allergies and intolerance.

Originally Published by Training Matters