How to manage constipation?

Management of Constipation

Polyethylene glycol (PEG) is strongly recommended as the first-line pharmacological treatment for chronic constipation due to its proven efficacy and favorable safety profile. 1

Step-by-Step Management Algorithm

Step 1: Non-Pharmacological Interventions

• Ensure adequate privacy and comfort during defecation
• Use proper positioning (small footstool to assist gravity)
• Increase fluid intake
• Increase physical activity and mobility within patient limits
• Attempt defecation 30 minutes after meals (utilizing the gastrocolic reflex)
• Optimize toileting schedule (attempt defecation at least twice daily, preferably 30 minutes after meals)
• Consider abdominal massage, which has shown efficacy in reducing gastrointestinal symptoms 1

Step 2: Initial Pharmacological Management

1. For mild constipation:

   • Trial of fiber supplementation (particularly psyllium) at doses >10g/day for at least 4 weeks 2
   • Note: Fiber should be taken with adequate fluid (8-10 ounces) 1
   • Caution: Avoid fiber in non-ambulatory patients with low fluid intake due to risk of obstruction 1

2. For moderate to severe constipation:

   • PEG 17g daily (strong recommendation, moderate certainty of evidence) 1
   • PEG has demonstrated durable response over 6 months 1
   • Common side effects: bloating, abdominal discomfort, and cramping

Step 3: Alternative or Additional Agents (if response is inadequate)

• Osmotic laxatives:

  • Lactulose 15g daily (safe in pregnancy) 1
  • Magnesium oxide 400-500mg daily (use cautiously in renal impairment) 1

• Stimulant laxatives:

  • Bisacodyl 5-10mg daily
  • Senna 8.6-17.2mg daily
  • Note: These are particularly useful for short-term use or rescue therapy 1

Step 4: For Refractory Constipation

• Reassess for cause and severity of constipation
• Rule out bowel obstruction
• Check for fecal impaction (digital rectal examination)
• Consider combination therapy (osmotic + stimulant)
• Consider adding prokinetic agent (e.g., metoclopramide 10-20mg PO three times daily) 1

Special Situations

Opioid-Induced Constipation (OIC)

• Prophylactic laxative therapy should be started when opioids are initiated 1
• Preferred options: stimulant laxatives (senna, bisacodyl) or osmotic laxatives (PEG) 1
• Avoid bulk laxatives like psyllium for OIC 1
• For refractory OIC, consider peripherally acting μ-opioid receptor antagonists 1

Fecal Impaction

• Digital fragmentation and extraction of stool
• Follow with enema (water or oil retention)
• Implement maintenance bowel regimen to prevent recurrence 1

Elderly Patients

• PEG (17g/day) offers efficacious and tolerable solution with good safety profile 1
• Avoid liquid paraffin in bed-bound patients and those with swallowing disorders 1
• Use magnesium-based laxatives cautiously due to risk of hypermagnesemia 1
• For swallowing difficulties or repeated impaction, consider rectal measures (suppositories, enemas) 1

Important Considerations and Pitfalls

• Enema contraindications: neutropenia, thrombocytopenia, paralytic ileus, intestinal obstruction, recent colorectal surgery, anal/rectal trauma, severe colitis, toxic megacolon, undiagnosed abdominal pain, recent pelvic radiotherapy 1

• Common errors to avoid:

  1. Inadequate fluid intake when increasing fiber
  2. Using bulk-forming agents in opioid-induced constipation
  3. Not adjusting laxative dose when increasing opioid dose
  4. Failure to recognize and treat fecal impaction before starting oral laxatives
  5. Not considering medication side effects as potential causes of constipation

• Treatment goals: One non-forced bowel movement every 1-2 days 1

By following this evidence-based approach to constipation management, most patients will experience significant symptom improvement and enhanced quality of life.