What is the approach to managing a patient with severe constipation lasting 1 month?

Management of Severe Constipation Lasting 1 Month

The management of severe constipation should begin with lifestyle modifications and fiber supplementation, followed by osmotic laxatives, stimulant laxatives, and specialized medications for refractory cases, with a systematic approach to rule out underlying causes. 1

Initial Assessment

• Rule out impaction, especially if diarrhea accompanies constipation (overflow around impaction) 2
• Rule out obstruction through physical examination, abdominal x-ray, and consider GI consultation 2
• Evaluate for underlying causes:
  • Medications (especially opioids)
  • Metabolic disorders (hypercalcemia, hypokalemia, hypothyroidism, diabetes mellitus)
  • Mechanical obstruction 2, 1
• Perform digital rectal examination to assess for fecal impaction 1

Step 1: Lifestyle and Dietary Modifications

• Increase fluid intake, particularly water 1
• Increase physical activity within patient limits 1
• Gradually increase fiber intake to 20-25g per day over several weeks 1
  • Focus on soluble fiber sources (fruits, vegetables, whole grains)
  • Avoid rapid increases which can cause bloating and flatulence
• Schedule toileting attempts 30 minutes after meals to take advantage of the gastrocolic reflex 1
• Optimize positioning during defecation (use a footstool) 1

Step 2: First-Line Pharmacologic Therapy

• For non-opioid induced constipation:

  • Begin with fiber supplements like psyllium (most effective fiber supplement) 1
  • Add polyethylene glycol (PEG) as the preferred osmotic laxative (17g/day) 1

• For opioid-induced constipation:

  • Discontinue any non-essential constipating medications 2
  • Start prophylactic stimulant laxative + stool softener (senna + docusate, 2-3 tablets BID-TID) 2
  • Increase laxative dose when increasing opioid dose 2
  • Goal: one non-forced bowel movement every 1-2 days 2

Step 3: Second-Line Therapy (If No Response Within 3-5 Days)

• Add or switch to other laxatives:
  • Bisacodyl 10-15 mg daily-TID 2
  • Polyethylene glycol (1 capful/8 oz water BID) 2
  • Lactulose 30-60 mL BID-QID 2
  • Magnesium hydroxide 30-60 mL daily-BID (use cautiously in renal impairment) 2, 1
  • Magnesium citrate 8 oz daily 2

Step 4: Management of Fecal Impaction

If impaction is present:

1. Perform manual disimpaction following pre-medication with analgesic ± anxiolytic 2
2. Administer glycerine suppository ± mineral oil retention enema 2
3. Consider tap water enema until clear 2
4. After disimpaction, implement maintenance bowel regimen to prevent recurrence 1

Step 5: Refractory Constipation Management

• Consider methylnaltrexone for opioid-induced constipation (0.15 mg/kg SC every other day) 2
• Consider prokinetic agent (metoclopramide 10-20 mg PO QID) 2
• Consider prucalopride for chronic idiopathic constipation (1-2 mg daily) 3
• Consider biofeedback therapy for defecatory disorders 1, 4

Monitoring and Follow-up

• Reassess for cause and severity of constipation 2
• Recheck for impaction or obstruction 2
• Continue to treat and monitor symptoms and quality of life 2
• Schedule follow-up within 2-4 weeks of initiating treatment 1

Common Pitfalls to Avoid

1. Failing to provide prophylactic laxatives when starting opioid therapy 1
2. Using bulk laxatives in non-ambulatory patients with low fluid intake (risk of mechanical obstruction) 1
3. Neglecting to implement a maintenance bowel regimen after treating fecal impaction 1
4. Using magnesium-based laxatives long-term due to potential toxicity 1
5. Overlooking the possibility of defecatory disorders, which often respond best to biofeedback therapy rather than laxatives 4, 5

By following this systematic approach, severe constipation can be effectively managed in most patients, improving their quality of life and preventing complications such as bowel obstruction or perforation.