Constipation is characterised by difficult or painful defaecation, and is associated with infrequent bowel evacuations, and hard, small faeces.
It is a very common cause of distress in palliative care patients. It is better to prevent it than to wait until treatment is needed.
When opioids are commenced it is almost always appropriate to start a laxative. Relatively high doses of laxative may be needed; the dose should be increased as the dose of opioid increases.
Constipation in patients with progressive disease is usually multifactorial.
Causes and effects
Causes to consider
- Drug induced – review medication; consider prophylactic laxative
- Dehydration - encourage fluids; review diuretics
- Reduced mobility - ensure ready access to toilet; attention to privacy, raised toilet seat for comfort
- Altered dietary intake - review and advise as appropriate
- Hypercalcaemia – consider treatment i/v fluids and bisphosphonates
- Neurological e.g. spinal cord compression; autonomic neuropathy
- Intestinal obstruction
Effects of chronic constipation
- spurious diarrhoea
- urinary retention
- mental confusion
Anticipate constipation; ask about previous bowel function, medications and other possible causative factors.
Exclude malignant intestinal obstruction. Abdominal palpation, auscultation and digital rectal examination are needed for proper assessment of constipation.
Investigations may be needed to guide treatment e.g. plain abdominal x-ray, calcium level to exclude hypercalcaemia.
Most palliative care patients are too debilitated to tolerate the dietary measures needed to combat constipation and to tolerate laxatives such as bulking agents. High fluid intake, fruit and fruit juice (especially prune juice) all help.
Laxative doses should be increased until constipation is controlled and may need to be higher than in other patients
- Use oral drugs first-line
- Patient preference may dictate choice
- Use a combination of:
- a stimulant laxative e.g. senna with
- a softener e.g. docusate or
- osmotic laxative e.g. macrogols
- Mixed preparations of softener and stimulant e.g. co-danthramer, keep medications to a minimum but may reduce flexibility of titration.
- Dantron containing products, co-danthramer and co-danthrusate have been restricted to constipation in terminally ill patients of all ages due to the theoretical risk as a carcinogen
- Do not use co-danthramer or co-danthrusate in patients who are incontinent of faeces, dantron can cause excoriation/burning of the skin. Dantron may also colour the urine red
- Any bowel stimulant can cause colic which may be avoided by using divided doses
- Lactulose is not routinely used in palliative care patients. It can cause excessive flatulence and abdominal cramps
- It is not normally necessary to use strong stimulant laxatives such as Picolax®
- Ispaghula husk is best avoided in patients that are unable to drink adequate volumes of fluid
- Manual evacuation should be the last resort and may need sedation or analgesia. Please seek specialist advice
- Subcutaneous methylnaltrexone bromide may be required for opioid induced constipation resistant to other treatment methods. Please seek specialist advice.
16. Palliative Care >
16.6 Constipation in palliative care
- First line
- Second line