What are the guidelines for treating constipation?

Guidelines for Treating Constipation

The first-line treatment for chronic idiopathic constipation should be fiber supplementation (14g/1,000 kcal daily) and polyethylene glycol (17g daily), followed by other osmotic laxatives if needed, with prescription medications reserved for refractory cases. 1

Initial Treatment Approach

Dietary and Lifestyle Modifications

• Increase dietary fiber to 14g/1,000 kcal intake per day, ensuring adequate hydration to prevent bloating and abdominal discomfort 1
• Increase fluid intake and physical activity within patient limits 2
• Ensure proper toileting position using a small footstool to assist gravity 2
• Establish regular toileting habits and ensure privacy and comfort 2

First-Line Pharmacological Treatment

• Osmotic Laxatives:

  • Polyethylene glycol (PEG): 17g daily, with no clear maximum dose; response has been shown to be durable over 6 months 1
  • Magnesium oxide: 400-500mg daily (use with caution in renal insufficiency) 1
  • Lactulose: 15g daily (only osmotic agent studied in pregnancy; may cause bloating and flatulence) 1

• Fiber Supplements:

  • Soluble fiber traps water in intestine and increases stool bulk 1
  • Cost typically less than $50 monthly 1
  • Titrate dose based on symptom response and side effects 1

Second-Line Treatment Options

Stimulant Laxatives

• Bisacodyl: Start with 5mg daily, maximum 10mg daily 1
• Senna: 8.6-17.2mg daily, with no clear maximum dose 1
• Recommended primarily for short-term use or rescue therapy due to potential for cramping, abdominal discomfort, and electrolyte imbalance with prolonged use 1

Prescription Medications for Refractory Constipation

• Secretagogues:

  • Lubiprostone: 24μg twice daily for chronic idiopathic constipation; may have benefit for abdominal pain 1
  • Linaclotide: 145mcg once daily for chronic idiopathic constipation in adults (72mcg daily may be used based on individual presentation or tolerability) 3
    • Take on empty stomach, at least 30 minutes before a meal 3

• Prokinetics:

  • Prucalopride: Strongly recommended for patients who don't respond to over-the-counter agents 1
    • Duration of treatment in trials was 4-24 weeks 1
    • May cause headache, abdominal pain, nausea, and diarrhea 1

Special Considerations

Management of Fecal Impaction

• Use glycerin suppositories or perform manual disimpaction if impaction is observed 2
• Suppositories and enemas are preferred first-line therapy when digital rectal examination identifies a full rectum 2
• Follow disimpaction with maintenance bowel regimen to prevent recurrence 2

Opioid-Induced Constipation

• Prophylactic treatment with stimulant laxatives is recommended 2
• Avoid bulk laxatives for opioid-induced constipation 2
• Consider peripherally restricted μ-opiate antagonists for refractory cases 4

Treatment Algorithm

1. Initial Approach:

   • Start with dietary fiber increase and PEG 17g daily 1
   • Ensure adequate hydration and physical activity 2

2. If Inadequate Response:

   • Add or switch to another osmotic laxative (magnesium oxide or lactulose) 1
   • Add stimulant laxative (bisacodyl or senna) as needed for rescue therapy 1

3. For Refractory Constipation:

   • Consider prescription medications (linaclotide, lubiprostone, or prucalopride) 1, 3
   • Evaluate for defecatory disorders or slow-transit constipation using studies of anorectal function and colonic transit 4

4. For Specific Situations:

   • For fecal impaction: Use suppositories, enemas, or manual disimpaction 2
   • For opioid-induced constipation: Use stimulant laxatives prophylactically 2

Common Pitfalls and Caveats

• Failure to ensure adequate hydration when increasing fiber intake can worsen constipation 1
• Long-term use of stimulant laxatives can cause electrolyte imbalances and dependency 1
• Magnesium-containing laxatives should be used with caution in patients with renal insufficiency 1
• Bulk laxatives are contraindicated in opioid-induced constipation 2
• Enemas are contraindicated in patients with neutropenia, thrombocytopenia, intestinal obstruction, recent colorectal surgery, severe colitis, or undiagnosed abdominal pain 2