This section covers the normal anatomy and physiology of micturition and defaecation, how continence is gained, and then describes how alterations from the normal can give rise to incontinence. It explores how continence is affected when ability to cope with activities of daily living change, and examines how society and its attitudes can affect elimination behaviour.

Continence is a skill gained when a person learns to recognize the need to pass urine and/or bowel motion, has the ability to reach an acceptable place to void, is able to hold on until they reach there and is able to void/eliminate effectively on reaching that place (Getliffe & Dolman 2007).

The first section examines the physiological mechanism used to achieve continence and then how it may fail and cause urinary and faecal incontinence. Other types of physiological failures that can cause problems with elimination are also considered.

Stress incontinence is more common than diabetes or asthma (Bishop 2005). It is defined as an involuntary loss of urine during increase in intra-abdominal pressure caused by laughing, sneezing or lifting. It occurs during the filling phase of the bladder causing leakage of urine. When the bladder is held in the correct position by the pelvic floor the inner closing mechanism and the external sphincter of the bladder prevent leakage (Fig. 18.5). If the pelvic floor is weak the bladder prolapses downwards and there is no compensatory pressure helping to counteract the pressure on the bladder and leakage may occur (see Fig. 18.5); this is made worse if the urethral closing mechanism is also weak, for example when oestrogen levels are low (Dolman 2007). Table 18.1 lists the common causes of stress incontinence.

Overactive bladder is characterized by involuntary bladder contractions during its filling phase and produces symptoms of urgency, frequency, urge incontinence, nocturia and nocturnal enuresis (see Table 18.2 for definitions of terms) (Wein et al 2002). The inhibition impulse from the cortical micturition centre of the cortex is not sufficient to prevent the sacral reflex action occurring, so the bladder starts to contract and voiding begins. This may be due to damage to the central nervous system, for example a cerebrovascular accident (stroke), tumours, spinal cord injuries or malfunction of the conduction of the nerve impulses, as seen in multiple sclerosis (MS) and Parkinsonism. Local bladder factors may be responsible for causing spasm that overrides cortical inhibition, for example caffeine (Bryant et al 2002), urinary tract infections, concentrated urine or external factors such as prostatic enlargement or constipation. Overactive bladder may occur in the absence of any detectable pathology (Fig. 18.6) (Getliffe & Dolman 2007).

There are two reasons for voiding difficulties and each is described in the following section.

There are other influences on the normal functioning bladder that may cause incontinence: these are fluid intake, urinary tract infection, drugs and constipation. The last two will be discussed later.

Many clients will cut down their fluid intake mistakenly believing it will reduce their incontinence. Concentrated urine will encourage bladder spasm and thus cause urgency and frequency (Getliff & Dolman 2007). This problem is also found in young children especially when starting school, unless encouraged to drink. They may drink minimal amounts, which may cause some girls to exhibit daytime wetting and may also be a factor in children who wet the bed (Butler et al 2005). The opposite problem sometimes occur in clients with learning disabilities who drink excessive amounts of water and produce large volumes of urine, causing frequency. Urinary tract infection will also cause bladder spasm giving urgency and frequency and may exacerbate urinary problems.

Faecal incontinence may occur when abdominal pressure increases for example when sneezing or lifting (see Fig. 18.11). It may be due to the following: damage of the anal sphincters, the pudendal nerve, weakness of the pelvic floor, (the puborectalis muscle) and increase of the anorectal angle (Norton & Chelvanayagam 2004). Damage to the internal or external anal sphincters (or both) due to forceps delivery or perineal tears during childbirth are often responsible for faecal incontinence in younger women (Porrett 2006). If the external sphincter is damaged, women may experience urgency, while damage to the internal sphincter may cause faecal seeping. Reduced muscle tone and nerve degeneration cause anorectal abnormality (Harari 2004).

A bad attack of diarrhoea may cause faecal incontinence, especially in those who are very ill, bed bound or have mobility problems. This may be due to infection or gastro-intestinal disease. Severe and prolonged attacks of diarrhoea should have a medical referral as should rectal bleeding (Norton & Chelvanayagam 2004).

Neurogenic bowel refers to constipation or faecal incontinence that occurs in patients with major neurological disease or injury, for example stroke or multiple sclerosis (Wiesel & Bell 2004). Spinal cord injury also leads to bowel dysfunction of varying types depending on the level and the degree of neurological completeness of the lesion (Ash 2005). The differences in the areas and seriousness of the neurological damage mean that management of this group must be individualized as there is a fine line between relieving constipation and causing faecal incontinence.

Elderly patients with dementia may be faecally incontinent due to decreased intellectual function, loss of social awareness and neurological sensation and an inability to control their bowels (Norton & Chelvanayagam 2004).

Constipation affects up to 27% of the population of the Western world (Lembo & Camilleri 2003). Faecal impaction can be the result of chronic constipation (Table 18.3) and may give rise to faecal incontinence of either solid or liquid stool (Norton & Chelvanayagam 2004). The latter is seepage from above the obstruction, and slime as a result of bacterial breaking down hard faeces and extra mucus. It is foul smelling and known as spurious diarrhoea. Thompson et al (1999) defined constipation as demonstrating two of the following symptoms: straining at stool; lumpy hard stools; sensation of incomplete emptying; and fewer than two bowel movements a week (ROME II criteria).

Faecal impaction may not always be due to large amounts of small hard stool but large amounts of soft faeces, when the client may be unable to completely empty from their bowel despite regular bowel movement. This can also cause faecal incontinence. The term ‘faecal loading’ may be the best term for this type of bowel problem (Barrett 2002). Impaction is often found in the frail elderly who may have impaired rectal sensation and thus do not initiate defaecation effectively (Harari 2002).

In summary, often continence difficulties in the elderly are multifactorial; for example, nocturia may be due to less efficient urine production, decreased antidiuretic hormone, bladder storage problems and sleep related issues (Wein et al 2002).

To acquire continence the child needs to develop physically, mentally and socially. During the first 18 months of life bladder emptying is purely a reflex action. The bladder is stable and empties completely, and Yeung et al (1995) found there is cerebral arousal during emptying. During the first 3 years of life the bladder capacity increases and the frequency of voiding decreases (Jansson et al 2000). Eventually the child then becomes aware of the urge sensation of passing urine and wanting to defaecate, associating this with feeling wet or soiled. The ability to control the bladder and anal sphincters and also the pelvic floor is developed. The sequence of developing control of elimination is normally bowel control when asleep, followed by the child being clean during the day, then the child gaining urinary continence during the day and finally becoming dry at night. There are a number of essential skills the child needs to develop before they are ready for toilet training (Schum et al 2002); gross motor skills of sitting and walking, the fine motor skills involved in dressing and undressing, and communication skills to alert their parent or carer that they need to go to the toilet are essential (Harris 2004). For children with special needs, this signal may be a non-verbal cue or a type of behaviour.

All these factors must be mastered to make ‘potty training’ successful. When the child has developed these diverse skills and is interested in using the toilet, they are ready for toilet training. Time should be given by the parent or carer to help the child get used to the potty or toilet, giving praise and encouragement when the child is successful. Toilet training takes time and accidents can occur, especially if the child is engrossed in play. This may upset the child and the parent.

Physical problems (illness) and emotional worries (parents’ divorce, starting school, etc.) may prolong toilet training, or even cause a child already trained to regress and start wetting again.

Nocturnal enuresis can be defined as involuntary voiding during sleep (Butler 2000). Children who have never been dry at night are classed as having primary nocturnal enuresis, whereas those who have been previously dry for 6 months or more are classed as having secondary nocturnal enuresis. Butler et al (2001) suggest that 15–22% of boys and 7–15% of girls wet the bed regularly at the age of 7 years.

It is thought that bed-wetting may be multifactorial (Enuresis Resource and Information Centre 2002), arising from the three following conditions, known as the ‘Three Systems Approach’:

Care pathways are vehicles for planning patient focused care. Accurate assessment of the individual with incontinence is essential to ensure that the reason for incontinence is found so a pathway with suitable interventions for the specific problems is identified (Brown et al 2006). The NICE guidelines for urinary incontinence (2006: 32) provide a good example of a care pathway for the management of urinary incontinence in women. Ideally the assessment will be multidisciplinary, involving doctors, nurses, physiotherapists and occupational therapists (NICE 2006).

When assessing and caring for a client with elimination difficulties nurses need to understand how the client and carer feel, and also to be aware of their own feelings towards the situation, so that negative attitudes are not transferred from the assessor to the client. The environment should be private and provide a relaxed atmosphere. The assessment should not be rushed and mutually understood terminology should be used. A holistic assessment should include the influencing and functional factors of incontinence as well as the urinary symptoms and specific physical examination (see Table 18.4).

The assessment should cover: