Effective intervention for constipation in elderly
Dr SK Matsiko discusses the causes of this condition and the role of laxatives and lifestyle changes
Constipation affects about 20 per cent of the elderly living in the community. The prevalence increases markedly for the elderly in care institutions, especially those who are chair- or bedbound. Some surveys suggest up to 8 per cent of these patients suffer from constipation. We spend about £46 million on prescribed laxatives every year.
Although constipation can cause misery in younger people, its effect on the quality of life of geriatric patients can be quite severe. It is one of the causes of the five giant Is of geriatric medicine: Instability (falls and dizziness), Immobility (taken to bed), Incontinence (of both urine and faeces), Impairment of cognitive function (confusion), and Iatrogenic (effects of the drugs).
With so much emphasis on preventing hospital admissions, I am often surprised at the number of 'social' admissions where constipation has not been considered in patients presenting with any of the above.
When evaluating an elderly patient with constipation, it is important to establish what the patient means by constipation. Definition of constipation varies widely. In the elderly it ranges from incomplete evacuation to absolute stoppage and obstruction. Preoccupation with bowel activity in the elderly often means extra care needs to be taken to understand what the patient means by constipation.
The common causes of constipation in the elderly include polypharmacy, co-morbidity, insufficient dietary fibre, and dehydration, as well as physical and metabolic disorders.
Many drugs cause constipation in the elderly including opiates, anticholinergics/antispasmodics, antidepressants, anticonvulsants, anti-anginals and antihypertensives.
Anti-parkinsonian agents, diuretics and antacids are also important.These are often taken in combination, and some have side-effects which themselves cause constipation as in diuretics causing hypokalaemia, hypomagnesaemia and uraemia. Metabolic disorders such as diabetes, hypothyroidism, hypercalcaemia and uraemia can lead to constipation in the elderly. Other causes include faulty habits such as low residue diet, poor fluid intake, lack of exercise and neglect of call to stool. The neglect of call to stool may be due to poor mobility, pain and lack of help if the patient is bed- or chairbound. Also, pain from fissures and piles as well as depression and dementia can lead a patient to ignore a call to stool.
Geriatric constipation may present in a variety of ways, including acute confusion, abdominal pain, acute retention of urine, faecal incontinence, nausea and vomiting from intestinal pseudo-obstruction, immobility and instability.
In evaluating elderly patients with constipation, care must be taken to get a comprehensive history from the patient or carers with the above in mind.
There are psychological barriers to overcome, but with care and sensitivity the full picture can be obtained. A full physical examination is mandatory, including a rectal examination. Patients may present with incontinence. Very often the GP is seeing the patient in a busy clinic but the examination is unlikely to be done in five minutes.
Rectal examination is one often-overlooked procedure, both in the community and hospitals, but it gives an instant diagnosis in the majority of cases.
Management obviously depends on the history and physical examination and the diagnosis. In the majority of cases, simple lifestyle changes can and will alleviate the symptoms.
Some patients will require enemas, but in all cases an attempt at making a diagnosis is imperative. Most constipation is due to insufficient dietary fibre and water, or poor caloric intake, and the patient will respond to a better diet.
Stoppage of the offending drugs in those with iatrogenic constipation is all that is required. In those whom the offending drug cannot be stopped, titrating laxatives against, say, the opiate would be appropriate. Correcting metabolic disorders where possible, rehydration and referral to hospital for those with suspected cancer are all necessary.
On the whole, for the frail or elderly on a minimalist diet, bulking laxatives are preferred. A rectal examination will quickly show the dry little pellets that often go with a low-fibre diet.
Patients with soft faeces on rectal examination would benefit from stimulant laxatives. Those with hard faeces may benefit from faecal softeners or osmotic laxatives. If there is a tendency to perianal pain as in fissures then faecal softeners should be used.
There is little evidence to support one class of laxative against another and so cost-effectiveness must be taken into account.
On the whole the elderly do not need to be on laxatives long-term or prophylactically. Laxatives should be used to re-establish normal bowel pattern and should be discontinued in favour of dietary modifications.
Rectal examination is often overlooked but can give an instant diagnosis~
Laxatives fall into these four groups
· Bulking agents such as bran and ispaghula husk
· Stimulant laxatives for example, senna and dioctyl
· Faecal softeners such as liquid paraffin
· Osmotic agents like magnesium hydroxide and lactulose
· In all cases establish a possible cause
· Remember the five giant Is: constipation can do it
· Do that rectal examination
· Dietary manipulation goes a long way
· Monitor continued need for the laxative