Faecal incontinence (FI) can be defined as a decline in bowel function that results in the involuntary loss of solid or liquid faeces (Menees et al, 2018). It is a common and distressing symptom that occurs at any age. There are numerous reasons why a person might lose control of their bowel function; the causes are multifactorial and often complex. It is important to recognise that while many of the causes of incontinence are not within the scope of the community nurse to change, many of the exacerbating factors are modifiable. This article highlights the importance of identifying FI and describes some of the structural and functional causes of this condition. Specific management will not be covered in this article as this was covered in an earlier issue in the series (Kelly, 2019).
While it should not be considered an expected outcome of advanced age, FI is more prevalent in older people. Statistics vary according to the definition of FI and research methodology used for analysis. A recent systematic review (Sharma et al, 2016) revealed that the prevalence estimates of FI among older people varied between 1.4 and 19.5%. However, one study found that up to 55% older people experience FI as compared with 18% people in the general population (Alavi et al, 2015). The higher estimate seems plausible, as FI is under-reported due to people being reticent to disclose this problem to a healthcare professional (NICE, 2007). Additionally, GPs' knowledge and awareness of the treatment and referral process for patients with FI is sometimes limited (Thekkinkattil et al, 2008). Community nurses are ideally placed to recognise and support older people who have FI, either through referral or specific advice in relation to symptom control.
Importance of treating FI in older people
When older people present with faecal incontinence, their condition is generally managed passively, with the use of pads, rather than a full assessment being completed (Harari, 2009). This may be due to some health professionals assuming that FI is an inevitable consequence of old age. There may also be the belief that very little can be done about the condition, and hence the dispensing of incontinence pads becomes the default management choice. However, a person's age does not disqualify them from receiving a thorough assessment, treatment and advice. Community nurses need to bear in mind that FI is not just an inconvenient physical occurrence with merely the need for a practical approach.
FI can affect a person psychologically, causing anxiety, which impacts social engagement (Ness, 2018), reduces self-esteem and is associated with altered body image (Collins and Norton, 2013). The person may lack confidence and be reluctant to leave their home, due to a fear of experiencing an episode in public. Subsequent restrictions in their lifestyle may lead to poor quality of life and cause the person to become socially isolated (Bartlett et al, 2009). This is extremely important when considering that as many as 8% of older people are depressed (Briggs et al, 2018) and many are at risk of social isolation (Medvene, 2016). Although rarely reported in the media, older people are among the group of people with the highest rate of suicide (Conejero et al, 2018). While the author is not making a direct association between FI and depression or suicide risk, it is important to be aware of the possible cascade of events that might occur if a person is left to live with debilitating symptoms that are potentially life-changing. Treating and managing FI is an important part of maintaining a person's independence, social life, confidence, self-esteem and personhood.
Having frequent episodes of FI can also contribute towards perianal dermatitis and the formation of moisture lesions on the skin (Butcher, 2017). Additionally, in older people with reduced mobility, hastening to the toilet with faecal urgency may trigger a fall. It can also lead to other health problems such as urinary tract infections (UTIs) (Meyer and Richter, 2015) through contamination with liquid stool. Falls and UTIs are well known to impact morbidity and mortality in older people. Further, FI is the most common reason why older people are admitted to care homes (Alavi et al, 2015).
Structural and functional causes
The most common cause of FI is dysfunction of the muscle groups of the pelvic floor. There is a multifaceted interaction between the pelvic floor muscles and the anal sphincters; impairment of any part of these can lead to loss of bowel control. The internal anal sphincter is an involuntary smooth muscle that is constantly in a contracted state to ensure that the anal canal is closed. It relaxes only when the person consciously chooses to open their bowels. Hence, during all other times, stool and flatus are prevented from leaking through. Damage to this muscle can, however, result in passive leakage of stool or flatus. The external anal sphincter (EAS) is a voluntary muscle that is squeezed only when the person is consciously deferring defaecation. Damage to the EAS can lead to episodes of urge FI.
The primary causes of structural damage to the pelvic floor are through obstetric injury (Smith et al, 2013) or anorectal surgery (Sharpe and Read, 2010) such as sphincterotomy, fistula surgery and haemorrhoidectomy. During pregnancy, the uterus places a strain on the pelvic structures. Vaginal deliveries can weaken the pelvic floor muscles (Zizzi et al, 2017), and women who deliver vaginally are more likely to experience episodes of incontinence than those who have had a caesarean section (Blomquist et al, 2018). Women may also experience a tear during delivery or injury from the use of forceps or vacuum-assisted delivery or have a prolonged second stage of labour (Williams et al, 2018). Often, symptoms of FI may not manifest until the person is older and the additional impact of age weakens the pelvic floor muscles to the extent to which symptoms are evident.
Incomplete evacuation
The inability to completely empty the bowel during defaecation is a major contributing factor to passive leakage of stool, but this is frequently overlooked (Harari, 2009). It is possible that health professionals rule out constipation as a factor in FI because it is considered within the symptomology of infrequent, hard stools. However, a person can pass soft stools daily but still have incomplete defaecation that results in incontinence. This is due to the incoordination of the muscles involved in defaecation (Collins and Norton, 2013). To pass stool effectively, the puborectalis, a muscle of the levator ani, relaxes and straightens the anorectal angle to allow stools to enter the anal canal. This is particularly apparent if the person is sitting in the squat position. Intra-abdominal pressure increases, the perineum descends and the anal sphincters relax to allow for stool to be effectively evacuated. Poor coordination of any aspect of this complex process can result in faecal retention. The subsequent pressure of the retained stool on the pelvic floor may lead to passive leakage of faeces, especially if there is also damage to the anal sphincters.
The presence of rectocele or a rectal prolapse is also a risk factor in the development of both incomplete evacuation and FI (Norton and Chelvanayagam, 2010). Having a BMI of over 35 also contributes to the risk of pelvic floor weakness, and obese women are more likely to experience episodes of FI than those with an average BMI are (Nazarko, 2018).
Loose stool
Stool that is loose or of liquid consistency is difficult to hold even in the absence of pelvic floor impairment. There are numerous reasons why a person might have loose stool. These range from eating spicy or high-fibre foods, having a high intake of products containing artificial sweeteners such as sorbitol (Ness, 2018) and consuming foods such as chocolate or licorice, which act as a laxative. Bacterial or viral infections of the gut are also likely to cause diarrhoea.
Disease processes such as inflammatory bowel disease including Crohn's disease and ulcerative colitis are important risk factors to a person experiencing FI. It is estimated that 24% people with inflammatory bowel disease experience FI (Norton et al, 2013). Similarly, functional disorders such as irritable bowel syndrome is associated with the experience of FI secondary to loose stools. One study revealed a prevalence of FI in 64% of people with irritable bowel syndrome who met the full Rome IV criteria for diagnosis (Hunt et al, 2018).
Neurological disorders
Neurological disease or injury is associated with a high risk of developing bowel control issues, as neural pathways are interrupted by the disease process. This can cause either constipation, incontinence or both and is referred to as ‘neurogenic bowel dysfunction’ (Kumar et al, 2016). FI has been reported in disorders such as spina bifida, spinal cord injury, cerebrovascular accidents, Parkinson's disease and multiple sclerosis (Norton and Chelvanayagam, 2010; Coggrave et al, 2014).
Cognitive impairment
The mechanisms through which a person with dementia might experience FI vary widely. People who are cognitively impaired can have incontinence as a result of any of the reasons described above. It may also be that the person has no structural or functional problem but forgets where the toilet is. This is particularly the case when a person with dementia is admitted to hospital and finds themselves in an unfamiliar environment. Episodes of incontinence are known to become more frequent at such times (Furlanetto et al, 2016). A person might no longer recognise the need to use the toilet (Russel et al, 2017) or the purpose of the toilet itself. This may be further impacted by visual impairment and poor mobility.
Conclusion
This article has described some of the main causes of FI in older people and has highlighted the importance of recognising symptoms and ensuring the person is supported with appropriate treatment, management, emotional understanding and support.