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Perspective on the paper by Loening‐Baucke (see page 486)
The relationship between constipation and faecal and urinary retention is very familiar to paediatricians, but the prevalence of these distressing symptoms appears to vary in the medical literature. We will explore the background to the development of continence and how this may be disturbed by constipation.
As Loening‐Baucke stresses in the article, the problem with literature review has been the lack of an agreed set of definitions for constipation. The Paris consensus has improved on the Rome II definitions and she has shown how valuable it is to apply these even in a retrospective notes survey.1 Her study also avoids the problem of extrapolating data from a referral centre to the whole community. As with any epidemiological study there may be characteristics of the community being studied that limit its generalisability. Loening‐Baucke's population is based on a university and so may not have an average socio‐economic profile. A population based study in the UK showed a prevalence in 7.5 year old children of infrequent daytime faecal incontinence (no more than once a week) of 6.8% and of severe incontinence (at least daily) of 0.8%.2
The acquisition of continence is an essential element for children to be able to fully integrate with others and to access most public activities. Delays or disruptions in achieving continence will severely limit social life and continence is an important marker of quality of life at any age beyond toddlerhood. Unless we have a reasonable understanding of the prevalence of incontinence, it is impossible to focus resources on this important problem. However, a clear measure is extremely difficult. A degree of incontinence for one child or family may be so acceptable that it is never mentioned but for another may be the reason for referral for medical help. Social constraints may also be driving factors for help being sought. For example, in the UK there has been an increase in the availability of preschool experience for children. If a preschool placement is dependent on a child being pot trained and out of nappies, a parent may seek medical help for a 2.5 year old who cannot reliably use the pot who would otherwise have been reassured to know that probably a half of healthy children of that age are equally unreliable about keeping their pants clean and dry.
To achieve continence the child must be able to perceive sensation arising from the bladder or rectum, assess the social consequences of passing urine and stool at that time, use appropriate voluntary muscles to delay micturition or defaecation and make plans to find a lavatory depending upon the urgency of the sensation. This is not an innate ability but requires learning in a supportive environment. Sensation of the need to pass stool by rectal smooth muscle contraction and reflex partial inhibition of the smooth muscle internal anal sphincter allows stool to impinge on the sensory area of the mucosa of the upper anal canal. The urgency of defaecation will depend on the degree of this inhibition and stool descent that can be temporarily relieved by external anal sphincter and pelvic floor contraction.
The sensation arising from bladder or rectal filling is slight or absent in neuropathic conditions such as neural tube defects, spinal injury or compression. Thus diligence is essential in examination the lower spine and sacrum together with the ankle reflexes for even subtle evidence of spinal dysraphism.3,4 Anything that disturbs learning of the link between the perception of bladder/rectal sensation and the social need to use the pot or lavatory is likely to delay acquisition of continence. Coercive pot training may feed into the natural defiant tendency of 2 year olds as they flex their self‐assertiveness. Pain related to excretion at this stage often leads to attempts to retain urine or stool (with associated strengthening of the pelvic floor muscles) which aggravates the tendency to urinary tract infection caused by incomplete bladder emptying, or withholding of faeces to the point of faecal impaction. This condition has been termed dysfunctional elimination. The situation for the rectum is complicated by the degree of megarectum. If the rectum has excessively high capacity then the anorectal inhibitory reflex is very brief until high volumes of stool are present. However, during these brief periods of anal canal inhibition, soft stool or pieces of dry stool can fall out without the rectal contractions or upper anal canal compression evoking a perceivable sensation. This can be mimicked with anorectal manometry where it is frequently observed that no sensation of a need to defaecate is reported until very high volumes of air are introduced into the distending rectal balloon despite brief (approximately 10 s) episodes of anal canal inhibition in association with provoked rectal contractions. A similar situation occurs with children who infrequently empty their bladders and appear to be unaware of bladder sensation until it reaches a critical stage and precipitate voiding does not allow them to reach the lavatory in time. Because wetting and faecal incontinence lead to peer and parental adverse pressure, the stress related to this may encourage the child to escape into dissociation and denial thus reducing their vigilance for sensations coming from these troubling areas. Vicious cycles are then set up which inevitably become more complex and interwoven with delays in active management of these problems. There has been a great deal of debate about whether the changes seen in bladder or rectal activity are primary or secondary to withholding. Fortunately, the basic management strategy of encouraging regular lavatory use, ensuring that this is as comfortable an experience as possible, with plenty of fluids in the case of the bladder and adequate stool softeners and stimulant laxatives to oppose faecal retention, leads to success if started early. Many other social and psychological factors influence the learning of effective continence such as regularity of lavatory use, and parents' ability to recognise when their child is about to pass urine or stool and speedily transport them to the pot or lavatory and then to welcome the result with praise rather than disgust. It is not surprising that neglected children are likely to have delayed continence. Distressed children are less likely to be in an environment that is conducive to effective pot/lavatory training and routines and may well have a degree of stress related enuresis and non‐retentive faecal incontinence. This situation is particularly difficult where a child has learning difficulties where delays in continence are in step with other developmental milestones. The mutual desire to please each other that is essential in the relationship between the child and parent is often very one‐sided with children on the autistic spectrum and it should not be surprising that continence problems often become intractable.
Loening‐Baucke reports the association between constipation and urinary incontinence in her population and this has previously been reported.5 Anyone who has performed a urinary tract ultrasound examination in a child who has a history of constipation will not be surprised by this association. Often the bladder is indented, compressed or misplaced laterally, sometimes to the point where the upper part of the bladder is seen in the vicinity of the liver or spleen. Incomplete bladder emptying may be a learned response of the fearful child attempting to withhold faeces. The social consequences of overflow faecal incontinence may also disturb the child to the point where urinary incontinence occurs as a result of stress. Even when a neuropathic condition has been excluded, there may be other factors that cause both constipation and urinary incontinence such as fear of lavatories (particularly dirty school lavatories), pain on micturition and defaecation as a result of skin disease such as lichen sclerosis et atrophicus,6 and also sadly penetrative sexual abuse. In addition, childhood bladder and bowel symptoms correlate well with ongoing bladder and bowel problems in adulthood.7 The precise relationship between bowel and bladder dysfunction does, however, require further clarification and recent evidence from the European Bladder Dysfunction Study refutes a causal relationship.8
The data that this paper provides should encourage those who influence health policy in giving continence problems in childhood the level of priority they deserve. Too often life spoiling conditions like these are neglected in the competition for scarce health resources. We have evidence that incontinence is common in young people in young offenders' institutions and we could speculate that the low self‐esteem resulting from poor continence could be one reason for adolescent antisocial behaviour and substance abuse. Early simple treatment is likely to benefit the majority of children when young and so avoid the complex psychological and physiological vicious cycles that go on to blight later childhood. The key to this is locally based provision of basic advice on adequate fluid intake, sensible and developmental age appropriate pot training and rapid access to effective medical treatment for urinary tract infection, overactive bladder and constipation when these are found. This means setting up more community based continence clinics for children and training for health professionals in this less than glamorous area.
Loening‐Baucke describes the prevalence of continence problems in her primary health care area and encourages us all to be aware of the level of these problems our own parts of the world. There is a human cost in neglecting this subject where timely advice and treatments can prevent escalating distress and its physical and psychosocial complications.
Competing interests: None.