What are the treatment options for constipation?

Treatment Options for Constipation

Polyethylene glycol (PEG) should be used as the first-line treatment for constipation, with a standard starting dose of 17g daily. 1

First-Line Treatment Approach

1. Initial Management:

   • Start with PEG 17g daily (can be increased to 34g if needed) 1
   • Ensure adequate hydration (2-3 liters daily unless contraindicated) 1
   • Establish a regular toileting routine, especially after meals 1
   • Increase physical activity 1
   • Increase dietary fiber to 25-30g daily 1

2. If inadequate response after 2-3 days:

   • Increase PEG dose by 50-100% (up to 34g daily) 1
   • Consider adding a stimulant laxative (e.g., senna, bisacodyl 5-10mg daily) 1

Alternative Laxative Options

If PEG is not tolerated or ineffective, consider these alternatives:

• Osmotic laxatives:

  • Lactulose: 15-30ml twice daily 1
  • Magnesium hydroxide: 30-60ml daily (avoid in renal impairment) 2, 1
  • Sorbitol: 30ml every 2 hours × 3 then as needed 2

• Stimulant laxatives:

  • Bisacodyl: 10-15mg daily (oral) or suppository daily 2, 1
  • Senna: 2 tablets every morning (maximum 8-12 tablets per day) 2

• Stool softeners:

  • Docusate sodium (less effective than other options) 3

Special Considerations for Opioid-Induced Constipation

Opioid-induced constipation requires a more aggressive approach:

1. Prophylactic regimen:

   • Start stimulant laxative plus stool softener when initiating opioid therapy 2
   • Increase laxative dose when increasing opioid dose 2
   • Avoid bulk-forming laxatives like psyllium as they may worsen symptoms 1

2. For established opioid-induced constipation:

   • Consider peripheral opioid antagonists:
     • Methylnaltrexone: 0.15mg/kg subcutaneously every other day 2, 1
     • Naldemedine or naloxegol (oral options) 1
   • Consider opioid rotation to fentanyl or methadone 1

Rescue Interventions for Severe Constipation

When oral medications fail:

• Check for fecal impaction before proceeding 2, 1
• Rectal interventions:
  • Suppositories (glycerin or bisacodyl) 1
  • Enemas (saline, Fleet, or tap water) 2
  • Caution: Enemas are contraindicated in neutropenia, thrombocytopenia, paralytic ileus, intestinal obstruction, recent colorectal surgery, anal/rectal trauma, or severe colitis 1

Monitoring and Treatment Goals

• Aim for one non-forced bowel movement every 1-2 days 2, 1
• Monitor for:
  • Stool frequency and consistency
  • Abdominal discomfort
  • Rectal bleeding (potential warning sign) 1, 4
  • Diarrhea (reduce dose of most recently added agent) 1, 4

When to Consider Referral

Consider referral to gastroenterology if constipation is refractory to aggressive medical management:

• For specialized testing (colonic manometry, defecography) 1
• For biofeedback therapy in cases of dyssynergic defecation 1, 5
• For consideration of surgical options in highly selected cases of slow-transit constipation 1

Common Pitfalls to Avoid

• Overreliance on bulk-forming agents: Psyllium and methylcellulose are not recommended as primary therapy for opioid-induced constipation 2, 1
• Inadequate fluid intake: Fiber supplementation without adequate hydration can worsen constipation 6
• Long-term use of magnesium-based laxatives: Can lead to potential toxicity, especially in those with renal impairment 3
• Prolonged laxative use without proper diagnosis: Laxatives should not be used for longer than 1 week without medical evaluation 4
• Missing alarm symptoms: Rectal bleeding, worsening abdominal pain, or persistent symptoms may indicate serious underlying conditions 4