What are the treatments for constipation?

Treatments for Constipation

For constipation management, polyethylene glycol (PEG) is the first-line treatment due to its proven efficacy and safety profile, while stimulant laxatives like senna are recommended for opioid-induced constipation. 1, 2

First-Line Treatments

Non-Pharmacological Approaches

• Increase fluid intake (especially for those with low fluid consumption) 1
• Increase physical activity within patient limits 1
• Ensure privacy and comfort for defecation 1
• Proper positioning (using a footstool can help with exerting pressure) 1
• Consider abdominal massage (particularly helpful for patients with neurogenic problems) 1

Pharmacological Options

For General Constipation:

1. Polyethylene glycol (PEG)

   • Dosage: 17g daily mixed in 8 ounces of water 1, 3
   • Produces bowel movement in 1-3 days 3
   • Strong evidence supports its use (moderate certainty of evidence) 1
   • Increases complete spontaneous bowel movements by 2.9 per week compared to placebo 1

2. Fiber supplements (for mild constipation)

   • Consider for mild symptoms or dietary fiber deficiency 1
   • Psyllium produces bowel movement in 12-72 hours 4
   • Should be taken with 8-10 ounces of fluid 1
   • Main side effect is flatulence 1
   • Note: Not recommended for opioid-induced constipation 2

For Opioid-Induced Constipation:

1. Stimulant laxatives

   • Senna (2 tablets every morning; maximum 8-12 tablets daily) 2
   • Bisacodyl (10-15 mg daily) 1, 2
   • Should be started prophylactically when initiating opioid therapy 1

2. PEG with 8 oz water twice daily (alternative to stimulant laxatives) 2

Second-Line Treatments

For Persistent Constipation:

• Osmotic laxatives

  • Lactulose (15-30ml twice daily) 2
  • Magnesium hydroxide (avoid in renal impairment) 1, 2
  • Sorbitol 1

• Rectal interventions (when digital rectal exam identifies full rectum or impaction)

  • Suppositories (glycerin) 1
  • Enemas (Fleet, saline, or tap water) 1
  • Manual disimpaction for fecal impaction 1

Third-Line Treatments (Refractory Constipation)

For Opioid-Induced Constipation:

• Peripherally acting μ-opioid receptor antagonists (PAMORAs)
  • Methylnaltrexone: 0.15 mg/kg subcutaneously every other day (no more than once daily) 1, 2
  • Naloxegol 1, 2
  • Naldemedine 2

Other Options:

• Prokinetic agents
  • Metoclopramide (consider for gastroparesis) 1
• Secretagogues
  • Lubiprostone 1
  • Linaclotide 1

Treatment Algorithm

1. Assess cause and severity of constipation

   • Rule out bowel obstruction or impaction 1
   • Check for metabolic causes (hypercalcemia, hypokalemia, hypothyroidism) 1
   • Identify medication-induced causes (especially opioids) 2

2. Start with appropriate first-line therapy

   • For general constipation: PEG 17g daily 1
   • For opioid-induced: Stimulant laxative or PEG 1, 2

3. If inadequate response after 1-2 days:

   • Increase dose of current therapy
   • Add or switch to osmotic laxative 1

4. For persistent constipation:

   • Add stimulant laxative if not already using 1
   • Consider rectal interventions for impaction 1

5. For refractory cases:

   • For opioid-induced constipation: Add PAMORA 1, 2
   • Consider specialty referral for defecatory disorders 5

Important Caveats

• Laxative dose should be increased when opioid dose increases 2
• Goal is one non-forced bowel movement every 1-2 days 1
• Avoid bulk-forming laxatives (psyllium) for opioid-induced constipation 2
• Stool softeners alone are insufficient for opioid-induced constipation 2
• PAMORAs are contraindicated in bowel obstruction 1
• Enemas are contraindicated in neutropenia, thrombocytopenia, paralytic ileus, intestinal obstruction, and recent colorectal surgery 1

By following this evidence-based approach to constipation management, most patients will experience relief while minimizing adverse effects.