What are the treatment options for constipation?

Treatment Options for Constipation

For most patients with constipation, polyethylene glycol (PEG) is the first-line treatment due to its proven efficacy, safety profile, and low cost. 1, 2, 3

First-Line Treatments

Osmotic Laxatives

• Polyethylene glycol (PEG): 17g daily mixed in 8oz water; can increase as needed

  • Strong recommendation with moderate-quality evidence 1
  • Produces bowel movements within 12-72 hours
  • Inexpensive (approximately $1/day) 1
  • Should be discontinued if diarrhea develops or if used for >1 week without physician consultation 4

• Magnesium salts (e.g., milk of magnesia): 30-60mL daily

  • Effective but use with caution in patients with renal impairment due to risk of hypermagnesemia 1, 2
  • Approximate cost: $1/day 1

• Lactulose: 30-60mL daily

  • Conditional recommendation with moderate evidence 1
  • May cause bloating and flatulence

Second-Line Treatments

Stimulant Laxatives

• Senna: 2 tablets daily (up to 8-12 tablets per day)

  • Good evidence for efficacy 3
  • Conditional recommendation 1
  • Often combined with stool softeners (docusate)
  • Approximate cost: $1/day 1

• Bisacodyl: 5-10mg daily orally or as suppository

  • Strong recommendation with moderate evidence 1
  • Best administered 30 minutes after a meal to synergize with gastrocolonic response 1
  • Can cause abdominal cramping

• Sodium picosulfate: 5-10mg daily

  • Strong recommendation with moderate evidence 1

Fiber Supplements

• Psyllium: 15g daily

  • Conditional recommendation 1
  • Effective for chronic constipation but not recommended for opioid-induced constipation 2, 5
  • Works best at doses >10g/day with treatment duration ≥4 weeks 5
  • Approximate cost: $1/day 1

• Methylcellulose: Effective for occasional constipation

  • Less gas-producing than psyllium 6
  • Ensure adequate fluid intake when using fiber supplements

Third-Line Treatments (Prescription Options)

Secretagogues

• Linaclotide: 72-145μg daily

  • Strong recommendation with high-quality evidence 1
  • Daily cost approximately $7-9 1

• Plecanatide: Strong recommendation 1

• Lubiprostone: 24μg twice daily

  • Conditional recommendation 1
  • Daily cost approximately $7-9 1

Prokinetics

• Prucalopride: Strong recommendation 1
  • Not available in the United States but approved in other countries 1

Special Considerations

Opioid-Induced Constipation

• All patients on opioids should receive prophylactic laxative therapy 2
• PEG is first-line, often combined with stimulant laxatives 2
• Avoid bulk-forming laxatives (psyllium) for opioid-induced constipation 2
• For refractory cases, consider methylnaltrexone 0.15mg/kg subcutaneously 1, 2

Defecatory Disorders

• Biofeedback therapy improves symptoms in >70% of patients 1
• Should be considered before laxatives for defecatory disorders (strong recommendation, high-quality evidence) 1

Elderly Patients

• Ensure access to toilets, especially with decreased mobility 1, 2
• PEG (17g/day) offers efficacious and tolerable solution 1
• Avoid liquid paraffin for bed-bound patients (risk of aspiration) 1, 2
• Use saline laxatives cautiously due to risk of hypermagnesemia 1, 2

Non-Pharmacological Approaches

• Increase dietary fiber (fruits, vegetables, whole grains)
• Maintain adequate fluid intake
• Regular physical activity as tolerated
• Optimize toileting position (use footstool)
• Attempt defecation 30 minutes after meals to utilize gastrocolic reflex 2
• Abdominal massage can help, particularly in patients with neurogenic problems 1

Treatment Algorithm

1. Start with lifestyle modifications + PEG 17g daily
2. If inadequate response after 1 week, add stimulant laxative (senna or bisacodyl)
3. For persistent symptoms, consider:
   • Increasing PEG dose
   • Switching to a different osmotic agent
   • Adding suppositories or enemas for rectal evacuation
4. For refractory cases, consider prescription medications (secretagogues or prokinetics)
5. For defecatory disorders, refer for biofeedback therapy

Cautions

• Rule out bowel obstruction before initiating therapy
• Discontinue laxatives if diarrhea develops
• Avoid bulk-forming agents in non-ambulatory patients with low fluid intake 1
• Enemas are contraindicated in patients with neutropenia, thrombocytopenia, recent colorectal surgery, and several other conditions 1