neostigmine is reserved for hospitalized patients with acute colonic pseudo‐obstruction, and benefit has been seen in the treatment of refractory constipation.73
Special categories of constipation
Medication use is strongly correlated with the development of constipation in older people. Where possible, unnecessary medications should be discontinued and necessary medications switched to a less‐constipating alternative when one is available. For example, verapamil causes more constipation than other calcium channel blockers. Opiate‐induced constipation should be managed as discussed above.
Randomized controlled trials have established that biofeedback therapy is effective, and it has become the mainstay treatment for dyssynergic defecation. It involves four to six sessions using visual and verbal feedback techniques to improve symptoms of chronic constipation. The goal is to restore a normal pattern of defecation with neuromuscular training. It aims to correct the incoordination of the pelvic floor and anal sphincters to achieve normal and complete evacuation.74 Second, it aims to increase rectal sensory perception in those patients who have impaired rectal sensation. The studies concluded that biofeedback therapy is a superior treatment compared to diet, exercise, laxatives, or diazepam for dyssynergic defecation.74
Individuals with dementia frequently develop constipation. Simple first‐line measures include reviewing prescription medications, increasing dietary fibre and fluid intake, and increasing activity levels. Sorbitol and lactulose have been reported to be successful treatments in an observational study, and regular use of an osmotic laxative was recommended to avoid the cost and discomfort of rectal laxatives.75 Prevention should be the preferred strategy, as people with dementia may have difficulty recognizing and communicating their symptoms effectively. Highlighting constipation as an important and reversible illness to relatives and carers aims to prevent constipation and hospitalization. Non‐verbal signs that the person may need to defecate include fidgeting, pacing, and pulling at their clothes. Helping the person identify where the toilet is can reduce them resisting their urge to defecate: for example, a clear sign on the bathroom door, an easy access route, and a contrasting toilet seat colour to aid identification. Timed toileting every 2 to 4 hours and 30 minutes after meals can improve continence and prevent constipation.
People with Parkinson’s disease can have a variety of non‐motor symptoms, including urinary disturbance, sialorrhea, anosmia, and abnormal sweating. Constipation commonly occurs in Parkinson’s disease related to dyssynergic defecation from incoordination of the pelvic floor musculature during defecation and the constipating effect of medication used to treat Parkinson’s disease. It is a key symptom that is an important feature to be elicited as it can lead to abdominal discomfort, nausea, and reduced appetite. Constipation has also been associated with reduced efficacy of medications due to reduced absorption. The treatment is as usual with a high fibre diet, increased fluid intake, and laxatives as required. Psyllium has been used successfully to treat constipation in these patients.76 Entacapone inhibits catechol‐O‐methyltransferase, preventing the peripheral breakdown of levodopa and allowing more levodopa to reach the brain. A side effect of entacapone is diarrhoea, so it can be a useful treatment if simple measures are ineffective.
Constipation after an acute stroke is common; the prevalence varies from 30 to 60%. The occurrence of constipation was found to be associated with increased dependency, use of the bedpan for defecation, and high National Institutes of Health Stroke Scale (NIHSS) score. Other possible risk factors included polypharmacy, dehydration, and physical inactivity. Constipation was associated with a poor outcome at 12 weeks.77 Chronic functional constipation is common in stroke survivors. Studies have demonstrated that colon transit is significantly reduced, attributed to the dysregulation of the central nervous system. A recent randomized controlled trial found that visceral mobilization improved symptoms of constipation, improving frequency of bowel movements, reducing abdominal pain, and reducing the sensation of an incomplete bowel movement.78 The results of a systematic review strongly suggest that abdominal massage can be effective in reducing the incidence and severity of constipation after stroke; however, further high‐quality studies need to be conducted to establish a definitive conclusion.79
The use of combinations of laxatives has rarely been addressed in the literature but is commonly encountered in practice when a single agent is ineffective. The most common combination is an osmotic laxative with a stimulant laxative. In patients with continued complaints of constipation despite the use of a single laxative, obtaining a plain abdominal radiograph to assess the degree of stool retention may be helpful. Patients with a large amount of stool (and no evidence of faecal impaction) may be treated with a colon preparation such as balanced electrolytes plus PEG (e.g. NuLYTELY) to cleanse the colon. The patient may be then started on an osmotic laxative with a stimulant laxative available on an as‐needed basis every two to three days if a satisfactory bowel movement does not occur.
Patients with refractory constipation and slow‐transit constipation may benefit from subtotal colectomy and ileorectostomy.80 Fortunately, this is rarely required as nearly 90% of patients with slow‐transit constipation respond to laxatives.81 When dyssynergic defecation is present, biofeedback improves defecatory function in around 70% of patients.82 Patients with both slow‐transit constipation and dyssynergic defecation should first be treated with biofeedback. When slow‐transit constipation persists after successful treatment of dyssynergic defecation, subtotal colectomy may be considered. Surgical therapy is most successful in patients without upper gut motility disorders or significant psychological symptoms.83 In patients with very refractory constipation, the use of antegrade enemas has been described.84,85 Antegrade enemas involve creating a caecostomy placed surgically or endoscopically. Water or PEG is flushed through the tube periodically to facilitate colonic emptying. No high‐quality, controlled trials have assessed any of these enema therapies, and the evidence of the risks and benefits remains limited.
The optimal treatment for faecal impaction is not clear. Patients able to tolerate oral therapy may benefit from PEG or other osmotic laxatives with or without the use of enemas.86 Patients with a hard or very large faecal bolus in the rectum may require manual removal of the faeces. Hyperosmotic, water‐soluble contrast enemas have also been used with success in relieving faecal impaction.87 Bulking agents should be avoided in this patient group.
Conclusion
Complaints of constipation and the use of laxatives remain common in older people. When controlling for comorbidities, constipation is no more common in elderly than in younger people. Stool frequency remains unchanged with ageing. Elders more commonly complain of straining and hard stools. Risk factors for constipation include medication use, chronic medical illness, and psychological distress. Healthy elders are no more likely to develop constipation than younger people. Constipation adversely affects elders’ sense of well‐being and quality of life. The economic impact is also significant due to the cost of laxatives alone. In patients with up‐to‐date colorectal cancer screening who lack worrisome symptoms such as bleeding or weight loss, empirical treatment is appropriate.
A step‐wise approach should be taken in the management of constipation. First, review medications causing constipation, and increase dietary fibre and fluid intake. There is limited evidence that making lifestyle changes resolves constipation, but it is universally accepted as an initial approach. Bulking agents can be added first‐line, then an osmotic laxative, and then a stimulant laxative if required. The safest, best‐tolerated and, least expensive laxatives should be implemented before prescribing the more expensive second‐line laxatives. Avoid bulking agents in the context of faecal impaction. A paucity of evidence is available to support the use of stool softeners. Patients who fail to respond require a more detailed evaluation.
Identifying the most effective treatment strategy for constipation in elders, whether in the community or long‐term care setting, remains unclear
