the frequency of faecal incontinence,43 although the dietary and lifestyle changes required to be eligible for bariatric surgery may also be relevant factors. Endocrine disorders leading to changes in bowel habit, such as constipation associated with hypothyroidism, may lead to impaction and subsequent faecal incontinence. Likewise, poorly controlled diabetes is associated with faecal incontinence, likely due to autonomic and peripheral neuropathy.44
Geriatric syndromes
As with urinary incontinence, the ability to defecate at a time and place of one’s own choosing relies on both physical and cognitive function. Locating suitable facilities requires integrating visual information to identify and visuospatial and executive function to plot a route to those facilities. The person will then need to rise, ambulate, disrobe, and sit before defecation can occur. A disorder that impairs these processes and their integration, including visual impairment or unfamiliar or poorly signposted toilets, such as those found in hospitals and care homes, will make it more challenging to locate facilities; and impairments to mobility, through sarcopenia, arthritis, or neurological conditions, including stroke, will make both reaching the toilet and getting into position to defecate more challenging and potentially lead to faecal incontinence. Unsurprisingly, faecal incontinence is more prevalent among nursing home residents than any other group.4 Walking aids such as frames can also impair the ability to access facilities, and adaptive devices such as raised toilet seats cause the rectum to straighten, making defecation more difficult.
Medications and drugs
Many medications can impact bowel function, usually inducing constipation, diarrhoea, or increased bowel transit leading to faecal urgency. These are summarized in Table 19.1.
Sequelae of faecal incontinence
Faecal incontinence is a marker for poor overall health and frailty and is associated with increased mortality in older adults, as well as institutionalization.8,45 Those with faecal incontinence have higher rates of urinary tract infection46 and significantly increased risk of pressure ulcers, particularly full‐thickness ulcers.47 Faecal incontinence is also associated with a significant reduction in quality of life. There are effects on the quality of life of both the sufferer and their family, as well as social isolation, impaired self‐esteem, and reduced sexual well‐being.5 Faeces are extremely damaging to skin, causing both direct damage and secondary infection with faecal organisms, and when mixed with urine, faecal urease causes urinary urea to be converted to ammonia, leading to greater skin damage.48
Table 19.1 Medications associated with faecal incontinence.
| Medications implicated in diarrhoea or loose stool |
|---|
| Metformin |
| Magnesium‐containing antacids |
| Proton pump inhibitors |
| Aminosalicylates |
| Digoxin |
| Methyldopa |
| Antibiotics |
| Acarbose |
| Colchicine |
| Non‐steroidal anti‐inflammatory drugs |
| Sorbitol (found in sugar‐free preparations and confectionary) |
| Laxatives |
| Medications inducing constipation |
| Opioids |
| Drugs with anticholinergic effects |
| Tricyclic antidepressants |
| OAB medications |
| Calcium channel blockers |
| Loperamide |
| Iron preparations |
| Drugs increasing GI motility |
| Metoclopramide |
| Macrolide antibiotics |
| Domperidone |
| Drugs that alter anal sphincter tone |
| Nitrates Beta blockers PDE‐5 inhibitors |
Faecal incontinence is associated with significant personal and healthcare resource use, although accurate data are sparse.6 Costs include both direct costs, such as containment products, care staff time, and laundry of clothes and bedsheets, and indirect costs, including work absenteeism of both the sufferer and their care partners, as well as dealing with complications of faecal incontinence such as UTIs. The total cost of faecal incontinence in the US is estimated to exceed $16 billion annually, and this is likely an underestimate.
Assessment of faecal incontinence
Given that people with faecal incontinence often will not volunteer that information, active case finding is essential in at‐risk groups, including those with frailty, neurological disease, or urinary incontinence and those taking potentially causative drugs such as opioids or metformin.
The goals of evaluating faecal incontinence in older adults should be to establish the frequency and severity of incontinence and the impact on the individual’s quality of life. Appropriate goal‐setting with the patient and their caregiver is essential, as well as exploring the extent to which treatment options are acceptable.
The mainstay of the assessment of faecal incontinence is the clinical history. This should include the duration of symptoms, frequency and consistence of normal, controlled bowel movements, frequency and consistency of faecal incontinence, and consistency to flatus. Objective assessment of stool consistency with the Bristol stool scale49 allows accurate and consistent description of stool types. An assessment of potentially contributing medical conditions as above, as well as a comprehensive drug history, including over‐the‐counter and dietary supplements, should also be taken. A functional history should be taken, covering the patient’s ability to identify and get to facilities and undress, get dressed, and wash their hands, as well as a description of the facilities available in the patient’s home, including access, grab rails, and the necessity to climb stairs. As with the assessment of urinary incontinence, asking the patient to go to the bathroom in the clinic and observing the process can be illuminating. A dietary history covering the intake of soluble and insoluble fibre, fruits, and vegetables is also important, and involving a dietician can be helpful.
The physical examination can help identify the underlying cause of faecal incontinence and should include as a minimum an abdominal examination, brief neurological examination, and digital rectal exam to assess anal tone, sensation, squeeze pressure, and faecal loading. The perineum should be inspected for dermatitis, haemorrhoids, surgical scars, fistulae, and rectal prolapse or ballooning of the perineum on straining, indicating weakness of the pelvic floor. In women, a vaginal exam to assess for posterior compartment prolapse should also be included. In those with a history or symptoms of cognitive impairment, a cognitive screening tool such as the Montreal Cognitive Assessment50 should be performed. The assessment of faecal incontinence is summarized in Table 19.2.