A common presentation to the general paediatric clinic is a child or young person’s difficult bowel habit, which is often a potent source of anxiety for parents and carers. A large proportion of these children will have a functional cause for their symptoms, with unnecessary investigation and non-evidence-based treatments adding to their difficulties. This article aims to explain what encompasses the normal bowel habit in children and young people, reassure where appropriate and identify those patterns that may be suggestive of a disorder or disease requiring treatment. We illustrate both extremes of the spectrum of normal bowel habit in children with two case studies.
- general paediatrics
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Case study 1: increased stool frequency
You see a healthy-looking 20-month-old toddler (Edward) who was brought by his mother, who was concerned about his stool pattern. He is passing 5–6 stools a day, described as mushy in consistency, with some undigested food (sweetcorn and peas) still visible. His stooling pattern has persisted since weaning. He passed meconium within 24 hours postnatally and was breastfed until 9 months of age before switching to formula when his mother returned to work. He is the first child, and Edward’s mother does not recall a preceding trigger, such as gastroenteritis.
Great variability exists within the normal range of stooling patterns of infants.1 The Avon Longitudinal Study of Parents And Children study, the largest longitudinal study of stool patterns in young children to date, established a mean stool frequency of 3 a day among 4-week-old infants. The range of stool frequency was wide but reduces with age, with most preschool children demonstrating a similar frequency of stooling with a mean of 1.3 stools a day (see table 1). In addition, infants and children undergo changes in stool colour and consistency that may further contribute to parental and carer anxieties regarding a normal bowel habit for their child.
In such cases, a history exploring parental ideas, concerns and expectations is key to the initial assessment, as well as any red flags that warrant investigation (see table 2). Identifying particular triggers, including changes in diet, illness or family life as well as concerns arising from the family history such as coeliac disease or food allergy are useful for planning investigations. The child with constipation and overflow, who presents with loose stools, should also be considered.
There is no particular family history of organic disease, but the mother describes a family history of irritable bowel syndrome (IBS). There are no identifiable dietary triggers obvious to the mother, and he is having a ‘healthy diet’ though, on further questioning, she admits he does like drinking very dilute squash and consumes approximately 2 L a day.
Diet is a useful aspect of the discussion as most parents are familiar with the concept of ‘what goes in the top end influences what comes out… as for a curry'’. Children receiving excessive vegetable matter or high fluid intake do have a tendency to looser, bulkier stools, due to a developing gut improving its ability for digestion, absorption and bowel transit. The consumption of excessive amounts of fruit juice may exacerbate diarrhoea due to high levels of fructose, especially in apple juice.2 Additionally, ‘sugar-free’ drinks often contain polyol sugars that cannot be absorbed and may cause osmotic diarrhoea. Aspects of the gastrointestinal system in the young child differ from older children and adults. Intestinal transit time is prolonged in neonates because of reduced motility and peristalsis, which improves by infancy.3 Immaturity of bile and pancreatic fluid secretion and reduced activity affects fat digestion in neonates and infants in the first few months. Fat-soluble vitamin (A, D and E) absorption is reduced in neonates, related to inadequate ileal bile salts, which improves by 1 year of age, and bile metabolism is equivalent to adulthood by the age of 4 years. The immature intestinal mucosa lowers motility and proteolytic enzymatic activity. Reduced IgA secretion, diminished number of B lymphocytes and higher intestinal permeability affect bacterial colonisation of the upper gastrointestinal tract. This also lowers defensive capacity and increases the absorption of proteins, immunoglobulins, carbohydrates, bacteria, virus and toxins. The infant microbiome rapidly develops from a sterile GI tract in fetal life, with bacteria detected within 4–8 hours of birth.4 The digestive tract colonisation itself affects bile salt metabolism and gastrointestinal motility and also depends on whether the neonate receives breast or formula milk. This colonisation continues to evolve into adulthood and beyond, affected continually by diet, infections and antibiotics. The average small intestine increases in both length and surface area through childhood, from 30 weeks’ gestation (200 cm), term (275 cm), 1 year (380 cm), 5 years (450 cm), 10 years (500 cm) and at adulthood (575 cm).5 Improvement ofcontinence is assistive: with colonic resorption of fluid, occurring with stool retention and helping symptom resolution in children with slightly looser stools. Children often experience symptom improvement around the age of 3–4 years as they enter school through improved gut absorption.
Edward is growing along the 75th centile for height and weight, in line with genetic potential, with no peripheral stigmata for chronic disease. His abdominal and perineal examination is unremarkable, with no faecal loading. His spinal inspection and lower limb reflexes are normal.
Assessment of growth and nutrition is imperative. Faltering growth (wasted buttocks and protuberant abdomen) in the presence of altered stool frequency raises the possibility of coeliac disease; also consider whether the child’s growth could be ‘catching down’ to their genetic potential. The child’s perineum and perianal area should be assessed, paying particular attention to the position and patency of the anus and any fissures or fistulae present, although Crohn’s disease is very rare in this age group.6 Associated nappy rash should be identified and treated accordingly.
This can be individualised to address specific parental concerns and any red flags on history and examination. A child with associated growth concerns or a family or personal history of thyroid disease or type 1 diabetes should be tested for Coeliac disease (tissue transglutaminase (TTG) IgA and total IgA) and hypothyroidism.7 If there are specific features in the history, for example, variation in the diet leading to symptoms, atopy or a family history of food allergy, a raised specific IgE can help ascertain the presence of an IgE-mediated food allergy. However, in the case of non-IgE-mediated food allergy, usually to cow’s milk protein or soy in infants and wheat in children, allergen-specific IgE and skin prick tests will be negative and therefore dietary manipulation is a more useful exercise. This requires strict elimination of a single food substance for a minimum of 3 weeks followed by slow reintroduction to assess the effect on symptoms.8 Pitfalls include not completely eliminating the food substance, not continuing the trial for long enough or not reintroducing the food gradually to conclude the test. If there is a history of preceding infection or blood in stools, a sample for microscopy, culture and sensitivity helps reassure parents regarding the absence of bacterial infection. When testing for Clostridium difficile, consider the high likelihood of C. difficile toxin excretion (up to 90%) in healthy children under the age of 2 years.9 Investigations for malabsorption include stool reducing substances and chromatography. A fresh stool sample (<2 hours old) is analysed, and the presence of reducing substances ≥0.5% suggests carbohydrate malabsorption but is unable to differentiate lactose from other monosaccharides such as fructose, glucose and galactose. Chromatography can then identify the reducing sugar as lactose to confirm a diagnosis of lactose intolerance but has a limiting turnaround time: both tests can be tricky for parents to supply a sample to the laboratory within the requisite 2 hours. An alternative test for lactose intolerance is the lactose hydrogen breath test, which has a diagnostic sensitivity of 40%–60% inevitably resulting in some diagnostic uncertainty.10 The poor sensitivity and specificity of these tests as diagnostic tools has resulted in the American Academy of Pediatrics diagnosing lactose intolerance based on the clinical picture followed by a trial of a lactose-free diet.11 Lactose intolerance is almost always secondary to a small bowel enteropathy, usually following gastroenteritis. Children displaying persistence of the classical symptoms of lactose intolerance (abdominal pain, bloating, flatus, diarrhoea, borborygmi and occasionally constipation) following the ingestion of lactose containing food should be considered for a lactose-exclusion diet until symptoms resolve, often by 4 weeks, and further investigation is recommended if symptoms persist longer. This should be done with clear written advice (see box 1: useful resources for parents) and the need for calcium supplementation considered. Once symptoms have subsided following full exclusion lactose can be gradually reintroduced as tolerated in an attempt to negate the risk of nutritional inadequacy. See table 3 fora summary of investigations.
Useful resources for parents
British Dietetic Association (BDA) (https://www.bda.uk.com/foodfacts/healthyeatingchildren.pdf).
ERIC: The Children’s Bowel and Bladder Charity (https://www.eric.org.uk/).
NHS Choices Lactose Intolerance (https://www.nhs.uk/conditions/lactose-intolerance/treatment/).
NICE guidance CG99: patient information (https://www.nice.org.uk/guidance/cg99/ifp/chapter/About-this-information).
Gluten Challenge advice (https://www.coeliac.org.au/uploads/65701/ufiles/Fact_sheets/GlutenChallenge.pdf).
Q: How much fibre should my child be eating?
Each meal should contain a starch (bread, rice, potato, pasta or breakfast cereal) and aim for five portions of fruit or vegetables a day (fresh, frozen, tinned, dried or juiced). Further information can be found on the British Dietetic Association website (see box 2).
Q: What about probiotics, do they work?
Probiotics are marketed as ‘good’ bacteria that aim to improve the balance of gut bacteria to improve health. They are generally considered safe in healthy children, but results of studies evaluating their use in functional gut disorders have been mixed.21 Parents wishing to trial the use of a probiotic should be advised to allow 4 weeks to notice a difference in their child’s symptoms. There is no evidence to promote one probiotic over another, but some children sensitive to cow’s milk may not tolerate those in milk drinks or yoghurts.
Q: Will my child always have problems with going to the toilet?
The variation in stool habit among healthy children reflects the natural growth and maturation of the gastrointestinal system from infancy to adulthood. Encouraging a healthy diet with adequate fibre and water intake and a positive approach to toileting will maximise the child’s chances of achieving a regular bowel habit.
Q: Will taking laxatives give my child a ‘lazy bowel’?
There is good evidence that taking laxatives to relieve constipation improves bowel function, and laxatives stopped too early affects symptom resolution. Laxatives can be necessary into the long term and are safe, with medical monitoring.
Edward’s investigations for coeliac disease and thyroid disorder were normal and stool culture was negative. He was reviewed 2 months later with no change in symptoms or growth parameters. His parents acknowledged trialling a wheat then dairy-free diet without improvement. They were reassured by the test results and were happy to watch for any red flag change in symptoms. They subsequently contacted their general practitioner (GP) to let them know that the symptoms had gradually improved without an obvious trigger.
In many children without red-flag symptoms or signs, reassurance and education are sufficient, assisted by normal investigations to exclude disease (see box 3: Rome IV criteria for the diagnosis of functional diarrhoea). Distinguishing at the outset in discussions with parents that interventions are aimed at improving function rather than treating disease is important at jointly establishing boundaries and managing expectations for improvement. The evidence base for all interventions is limited and often based on expert opinion. Parents will often wish to discuss dietary manipulation. The benefit of dietary exclusions should be put in context with the third of adults with IBS whose symptoms improve on a wheat-free diet. There are no data estimating the placebo effect in paediatric IBS, but studies suggest the placebo effect in adults with IBS is approximately 37.5%,12 and in paediatric migraine, the placebo effect is approximately 50%, with other factors such as natural resolution confounding the data.13 Excessive dietary restrictions may result in nutritional deficiency and should be discouraged. However, reducing a child’s fruit squash intake and encouraging a normal fruit and vegetable intake are useful starting points. A short-term trial of loperamide for children with functional diarrhoea undergoing potty training as an attempt to ‘reset the clock’ should be considered; however, the success rate for empirical laxative or loperamide treatment is poor and can cause side effects such as abdominal cramps and worsening incontinence. Probiotics are, to date, only recommended in antibiotic-associated diarrhoea, and NICE recommend their use in persistent infectious diarrhoea (in a Cochrane review meta-analysis probiotics reduced the duration of persistent (>14 days) diarrhoea (mean difference 4.02 days, 95% CI 4.61 to 3.43 days, n=324, two trials).14 15 However, superiority of any specific probiotic has not been demonstrated.16
Rome IV criteria for the diagnosis of functional diarrhoea20
Daily, painless, recurrent passage of four or more large, unformed stools.
Symptoms last more than 4 weeks.
Onset between 6 months and 5 years of age.
No failure to thrive provided caloric intake is adequate.
Functional diarrhoea is common and in the absence of red flags, reassurance, analysis of stool to exclude infection, reduction of excess fruit juice and normalising vegetable intake is sufficient, given the likelihood of improvement over time. Further targeted testing can be considered if particular risk factors are identified.
Case study 2: reduced stool frequency
You assess a 5-year-old girl (Jennifer) who has been visiting the GP regularly with complaints of tummy ache and infrequent passage of stools. She is otherwise well and has had no admissions to hospital or contact with a paediatrician. She used to pass normal stools on a daily basis until 6 months ago when she started school. Since then her parents have noticed she can easily go 3 days between opening her bowels.
The parents and carers of infants and children who pass stools less frequently, but within the limits of normality, may fear that their child is constipated. Once again, the history should be used to identify any red flag symptoms (see table 2) and differentiate the child with a possible organic cause of reduced stool frequency from the healthy child whose bowel habit falls within the spectrum of normal for their age. In Jennifer’s case, her parents have identified a potential trigger for her change in bowel habit, which should be further explored with both Jennifer and her parents.
Jennifer’s parents deny any red flag symptoms and say she is enjoying school, has a good appetite and eats a healthy, varied diet. When asked, Jennifer says she does not like going to the toilet at school and gets embarrassed talking about it. Jennifer’s parents say her stools are hard but do not block the toilet, and she has not experienced any episodes of soiling or bleeding associated with the passage of her stools. Her tummy ache settles with the passage of a stool.
Jennifer is growing along the 50th centile for height and weight, in line with genetic potential, with no peripheral stigmata for chronic disease. Abdominal palpation reveals faecal loading in the left iliac fossa. Her spinal inspection and lower limb reflexes are normal.
As with the previous case, examination should include assessment of growth and nutrition. Abdominal examination should be performed, and any faecal loading was explained and potentially demonstrated to the parents. Showing palpation of the left iliac fossa to parents is useful: ‘like rolling dough on the Great British Bake-Off’. The spine should be examined for cutaneous stigmata suggestive of spinal dysraphisms and assessing lower limb reflexes helps to exclude a neurological cause of reduced stool frequency. NICE recommend that digital rectal examination may be considered but should only be performed once and only by a paediatric specialist if pathology is suspected.7
In the absence of faltering growth or any other red flags, testing for hypothyroidism is not indicated, and routine allergy testing to diagnose cow’s milk protein allergy is not recommended.17 The British and European societites for Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN and ESPGHAN) do, however, recommend checking IgA and TTG in children with constipation in view of the fact that most children with newly diagnosed coeliac disease do not have faltering growth or signs of malabsorption. Abdominal ultrasound scan and X-ray are not a useful tool in the diagnosis of constipation and should not be performed routinely.18
Infants and children who fulfil the Rome IV criteria for the diagnosis of functional constipation (see box 4) should be managed in accordance with the NICE clinical guideline (CG99): constipation in children and young people: diagnosis and management, which includes a detailed discussion regarding medications.7 Children who experience difficulties passing regular stools but do not meet the Rome IV criteria and have no red flags on history and examination should be managed with reassurance and lifestyle advice. Parents should be encouraged to adopt a negotiated and non-punitive approach to helping the child achieve a regular bowel habit. Behavioural changes include regular toileting with the use of a foot stool for younger children and a reward system for any bowel motion passed. A bowel diary may also be useful, and advising parents to liaise with the school nurse to encourage the child to use the toilet at school may prove beneficial, for example, providing a ‘toilet pass’ and access to a clean, separate toilet. Parents should be educated on the dietary factors that will reduce the degree of constipation including sufficient fibre intake (fruit, vegetables, wholemeal bread, wholegrain breakfast cereals and baked beans) and adequate fluid intake to keep stools soft.
Rome IV criteria for the diagnosis of functional constipation20
Must include 1 month of at least two of the following in infants up to 4 years of age:
Two or fewer defecations per week.
History of excessive stool retention.
History of painful or hard bowel movements.
History of large-diameter stools.
Presence of a large faecal mass in the rectum.
In toilet-trained children, the following additional criteria may be used:
At least one episode per week of incontinence after acquisition of toileting skills.
History of large-diameter stools that may obstruct the toilet.
If the main presenting feature in very young children is of straining while passing normal stools, consider infant dyschezia.19 The infant will appear distressed and continue to strain until there is passage of soft or liquid stool. Parents may describe trying to alleviate the child’s perceived pain by stimulating the anus with a suppository or a thermometer, an act that usually leads to stooling and resolution of the distressed behaviour. This ‘success’ may then reinforce this intervention. The underlying cause may be failure to coordinate increased intra-abdominal pressure with relaxation of the pelvic floor. Simultaneous abdominal and gluteal contractions interfere with defaecation. Unlike colic, the distress is only associated with defaecation. The symptoms start in the first months of life and often resolve spontaneously within a few weeks, as the infant learns appropriate coordination. Listening to the parents’ worries and performing a thorough physical examination (including anal inspection) to exclude associated constipation is essential. In the absence of symptoms or signs of underlying disease, explaining that this is a benign phenomenon and no testing or treatment is necessary will reassure parents. Repeated anal stimulation or glycerine suppositories should be discouraged as a means to help the infant to learn the correct defaecationprocess.
Children who pass stools infrequently may be perceived by their parents as being constipated. In many cases, these children will not meet the Rome IV criteria for functional constipation but will actually fall within the spectrum of normal bowel habit for their age. Recognition of their bowel habit as normal variation and providing advice and reassurance will prevent overmedicalisation. Children with abdominal pain and painful stools should be provided with practical steps that can be taken in addition to medications for constipation. Helping parents and children with advice to achieve continence can help prevent many years of struggling with constipation and overcome the associated embarrassment and impact on schooling. A selection of parental frequently asked questions and how to address them are listed in box 2, and useful resources for parents can be found in box 1.
Test your knowledge
In an 18-month-old boy with frequent stools, which of these symptoms would be regarded as ‘red flag’?
Three stools a day
Family history of coeliac disease
Which of these interventions has an evidence-base in treating an 18 month old with loose stools:
Reducing dilute squash intake
Explanation and Reassurance
In a 4 year old with difficulty in defaecation: in addition to treatment, what lifestyle recommendations would you advise?
Positive approach to regular toileting with reward system.
Liaising with school (providing ‘toilet pass’ and access to a clean, separate toilet).
Ensuring sufficient fibre intake.
Ensuring adequate fluid intake to keep stools soft.
Social stories to help understanding.
What investigations would you perform in a 4 year old with constipation without ‘red flags’ of concern?
Thyroid function tests.
Tissue transglutaminase IgA with total IgA.
Abdominal ultrasound scan
Answers to the quiz are at the end of the references.
Answers to the multiple choice questions
A, C and E.
A and E.
A, B, C, D and E.
B (if having more than 10 g gluten in diet a day).
Contributors MPT conceived the article. JC wrote the article, and both authors edited the article. MPT acts as guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Commissioned; externally peer reviewed.
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