Management of Constipation in Palliative Care
The optimal approach to managing constipation in palliative care requires a stepwise, proactive strategy with prophylactic laxatives, particularly for patients on opioids, using a combination of stimulant laxatives and stool softeners with a goal of one non-forced bowel movement every 1-2 days. 1
Assessment and Causes
- Rule out impaction (especially if diarrhea accompanies constipation due to overflow around impaction) and obstruction through physical exam and abdominal x-ray 1
- Identify and treat reversible causes including hypercalcemia, hypokalemia, hypothyroidism, diabetes mellitus, and medication effects 1
- Discontinue any non-essential constipating medications 1, 2
- Consider plain abdominal X-ray to assess extent of fecal loading and exclude bowel obstruction in severe cases 1
Management Algorithm Based on Prognosis
For Patients with Years of Life Expectancy:
- Increase fluid intake and encourage physical activity 1
- Increase dietary fiber only if patient has adequate fluid intake and physical activity 1
- Administer prophylactic laxatives, especially when starting opioids 1, 3
For Patients with Months to a Year of Life Expectancy:
- Add and titrate bisacodyl 10-15 mg daily to TID with goal of one non-forced bowel movement every 1-2 days 1
- Continue to monitor symptoms and quality of life with ongoing reassessment 1
For Patients with Weeks to Months of Life Expectancy:
- Administer glycerine suppository with or without mineral oil retention enema 1
- If impacted, perform manual disimpaction following pre-medication with analgesic and anxiolytic 1
- Consider additional laxatives such as:
- For opioid-induced constipation, consider methylnaltrexone 0.15 mg/kg subcutaneously every other day (except in post-op ileus and mechanical bowel obstruction) 1, 2
- Consider a prokinetic agent (metoclopramide 10-20 mg PO QID) 1, 3
For Dying Patients (Days to Weeks):
- Increase dose of laxative with or without stool softener (senna with or without docusate, 2-3 tablets BID-TID) 1
- Maintain goal of one non-forced bowel movement every 1-2 days 1
- Intensify palliative care interventions as needed 1
Pharmacological Approach
- First-line: Combination of a stimulant laxative (senna, bisacodyl) with or without a stool softener 1, 6
- Evidence suggests stool softeners alone (docusate) may not be necessary when using stimulant laxatives effectively 1
- Second-line: Add osmotic laxatives (polyethylene glycol, lactulose, magnesium preparations) 1, 7
- For opioid-induced constipation: Consider peripherally acting μ-opioid receptor antagonists like methylnaltrexone 1, 7, 2
- Newer agents that may be considered in refractory cases:
Common Pitfalls to Avoid
- Failing to provide prophylactic laxatives when starting opioid therapy 3, 2
- Relying solely on stool softeners without stimulant laxatives 1, 3
- Depending exclusively on lifestyle modifications without pharmacological intervention in advanced disease 1, 6
- Overlooking impaction as a cause of apparent diarrhea (overflow) 1
- Using methylnaltrexone in patients with bowel obstruction 1, 2
Non-Pharmacological Approaches
- Ensure privacy and comfort for normal defecation 1
- Proper positioning (small footstool may help exert pressure more easily) 1
- Consider abdominal massage, which has shown efficacy in neurological conditions and may benefit palliative patients 1
- Maintain mobility when possible, even if limited to bed-to-chair transfers 1, 7
Despite the frequency of constipation in palliative care, the evidence base for management remains limited 8, 9. Current recommendations are based primarily on expert consensus rather than high-quality randomized controlled trials 6, 8. A systematic approach tailored to the patient's prognosis and underlying causes remains the most effective strategy.