What are the treatment options for constipation?

Treatment Options for Constipation

For most patients with constipation, a stepwise approach starting with lifestyle modifications followed by osmotic or stimulant laxatives is recommended as first-line treatment. 1, 2

Initial Assessment

• Evaluate for possible causes of constipation including medication review, physical examination with abdominal assessment, perineal inspection, and digital rectal examination 2, 1
• Check corrected calcium levels and thyroid function if clinically indicated 1
• Consider plain abdominal X-ray to assess fecal loading and exclude bowel obstruction in severe cases 2, 1

Non-Pharmacological Interventions (First Line)

• Ensure privacy and comfort for normal defecation 2, 1
• Optimize positioning (using a small footstool can help apply pressure more effectively) 1
• Increase fluid intake (at least 2L daily) 1, 3
• Increase physical activity and mobility within patient limits 2, 1
• Increase dietary fiber intake if fluid intake is adequate 2, 1
• Consider abdominal massage, which can be effective in reducing gastrointestinal symptoms, particularly in patients with neurological problems 2, 1

Pharmacological Management (When Lifestyle Changes Are Insufficient)

First-Line Laxatives

• Osmotic laxatives (preferred first option) 2, 1:

  • Polyethylene glycol (PEG): 17g/day with 8oz water 1-2 times daily; virtually no electrolyte imbalances 2
  • Lactulose: May cause bloating and abdominal discomfort 2
  • Magnesium salts: Use cautiously in renal impairment due to risk of hypermagnesemia 2

• Stimulant laxatives 2:

  • Bisacodyl: 10-15mg, 2-3 times daily 2
  • Senna: Best taken in the evening to produce morning bowel movement 2
  • Sodium picosulfate: For short-term use in refractory constipation 2

Second-Line Options

• For persistent constipation: Add rectal bisacodyl once daily or increase osmotic laxative dosage 2
• For opioid-induced constipation (OIC):
  • Prophylactic laxative regimen should be started when opioids are prescribed 2
  • Methylnaltrexone: 0.15mg/kg subcutaneously every other day (not more than once daily) for OIC that hasn't responded to standard laxatives 2, 1
  • Combined opioid/naloxone medications can reduce risk of OIC 2

Third-Line Options

• Secretagogues for refractory constipation 2:
  • Linaclotide: FDA-approved for irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation in adults 4
  • Lubiprostone: Effective for treating OIC in patients with chronic non-cancer pain 2

Special Situations

Fecal Impaction

• If impaction is present, use glycerin suppositories or perform manual disimpaction 2
• Follow with maintenance bowel regimen to prevent recurrence 2

Elderly Patients

• Pay particular attention to assessment of elderly patients 2
• Ensure access to toilets, especially for those with decreased mobility 2
• PEG (17g/day) is considered safe and effective in elderly patients 1, 5
• Avoid liquid paraffin in bedridden patients due to risk of aspiration 1

Opioid-Induced Constipation

• Prophylactic bowel regimen is essential; stimulant laxatives with or without stool softeners are recommended 2
• Bulk laxatives like psyllium are not recommended for OIC 2
• Consider peripherally acting μ-opioid receptor antagonists (PAMORAs) like methylnaltrexone for refractory cases 2

Important Considerations

• Constipation affects approximately 50% of patients with advanced cancer and most patients on opioid therapy 1
• Discontinue non-essential constipating medications when possible 1
• Monitor renal/cardiac function in patients on diuretics or cardiac glycosides due to risk of dehydration and electrolyte imbalances 1
• Stool softeners alone (like docusate) are less effective than stimulant laxatives 2, 6
• If constipation persists despite optimal management, consider referral for specialized testing (anorectal physiology tests, assessment of colorectal transit time) 6