What are the treatment options for constipation?

Treatment Options for Constipation

The first-line treatment for constipation should include preventive measures such as increased fluid intake, physical activity, and a stimulant laxative, with osmotic laxatives added if response is inadequate. 1

Assessment of Constipation

Before initiating treatment, it's important to:

• Assess for cause and severity of constipation
• Rule out bowel obstruction and impaction
• Evaluate for other treatable causes (hypercalcemia, hypokalemia, hypothyroidism, diabetes mellitus)
• Identify medications that may cause constipation (antacids, anticholinergics, opioids)

Treatment Algorithm

First-Line Interventions:

1. Non-pharmacological measures:

   • Ensure privacy and comfort for defecation
   • Proper positioning (small footstool to assist with defecation)
   • Increased fluid intake
   • Increased physical activity within patient limits
   • Optimized toileting (attempt defecation 30 minutes after meals) 1

2. Dietary modifications:

   • Increased dietary fiber (if adequate fluid intake) 1
   • Note: Bulk laxatives such as psyllium are NOT recommended for opioid-induced constipation 1

3. First-line laxatives:

   • Stimulant laxatives: Senna (2 tablets every morning; maximum 8-12 tablets per day), bisacodyl (10-15 mg, 2-3 times daily) 1
   • Osmotic laxatives: Polyethylene glycol (PEG), lactulose, magnesium hydroxide, or magnesium citrate 1
   • Goal: One non-forced bowel movement every 1-2 days 1

Second-Line Interventions (if constipation persists):

1. Rectal interventions (if impaction is present):

   • Glycerine suppositories
   • Rectal bisacodyl once daily
   • Manual disimpaction if necessary 1

2. Additional oral agents:

   • Increase dose of current laxatives
   • Add prokinetic agent (e.g., metoclopramide) if gastroparesis is suspected 1

Third-Line Interventions (for refractory constipation):

1. Peripherally acting μ-opioid receptor antagonists (for opioid-induced constipation):

   • Methylnaltrexone 0.15 mg/kg subcutaneously every other day (no more than once daily) 1
   • Naloxegol (for patients receiving chronic opioids) 1

2. Newer agents:

   • Lubiprostone (activates chloride channels to enhance intestinal fluid secretion)
   • Linaclotide (selective agonist of guanylate cyclase-C receptors) - FDA approved for chronic idiopathic constipation and irritable bowel syndrome with constipation 1, 2

Special Considerations

Opioid-Induced Constipation:

• Prophylactic laxative therapy should be initiated when opioids are prescribed 1
• Stimulant laxatives are preferred first-line therapy 1
• Consider peripherally acting μ-opioid receptor antagonists if standard laxatives fail 1
• Combined opiate/naloxone medications may reduce risk of opioid-induced constipation 1

Elderly Patients:

• Ensure access to toilets, especially for those with decreased mobility
• Provide dietetic support
• PEG (17 g/day) is efficacious and well-tolerated in elderly patients
• Avoid liquid paraffin for bed-bound patients or those with swallowing disorders
• Use magnesium-containing laxatives with caution due to risk of hypermagnesemia 1

Common Pitfalls to Avoid

1. Inadequate initial assessment: Failing to rule out serious causes of constipation like obstruction or impaction

2. Inappropriate fiber use: Adding dietary fiber without adequate fluid intake can worsen constipation; bulk laxatives are contraindicated in opioid-induced constipation 1

3. Insufficient laxative dosing: Inadequate dosing of laxatives is a common reason for treatment failure

4. Overlooking medication causes: Not discontinuing or adjusting medications that cause constipation

5. Delayed escalation of therapy: Waiting too long before advancing to second-line treatments when first-line measures fail

6. Enema contraindications: Using enemas in patients with neutropenia, thrombocytopenia, paralytic ileus, intestinal obstruction, or recent colorectal surgery 1

By following this structured approach to constipation management, most patients will experience significant improvement in symptoms and quality of life.