What are the treatment options for constipation in a hospital setting?

Treatment Options for Constipation in Hospital Settings

The management of constipation in hospitalized patients should follow a stepwise approach starting with non-pharmacological interventions, followed by osmotic laxatives like polyethylene glycol as first-line pharmacological therapy, with stimulant laxatives as second-line or adjunctive therapy. 1, 2

Initial Assessment and Non-Pharmacological Interventions

• Rule out complications first:

  • Check for impaction (especially if diarrhea accompanies constipation - may indicate overflow)
  • Rule out obstruction through physical exam and abdominal imaging if needed
  • Identify other causes (hypercalcemia, hypokalemia, hypothyroidism, diabetes, medications) 1

• Non-pharmacological measures:

  • Increase fluid intake
  • Increase dietary fiber (only if adequate fluid intake and physical activity)
  • Encourage physical activity/exercise when appropriate
  • Establish proper toileting routine and positioning 1, 2
  • Discontinue non-essential constipating medications 1

Pharmacological Management

First-Line Agents:

• Osmotic Laxatives:

  • Polyethylene glycol (PEG): 17-34g daily (1 capful/8 oz water BID)
    • Mechanism: Draws water into intestinal lumen
    • Response time: 1-3 days
    • FDA warning: Not for use >1 week without medical supervision 3, 2

• Alternative Osmotic Agents:

  • Lactulose: 30-60 mL BID-QID
  • Sorbitol: 30 mL every 2 hours × 3, then PRN
  • Magnesium hydroxide: 30-60 mL daily-BID (avoid in renal impairment)
  • Magnesium citrate: 8 oz daily 1, 2

Second-Line/Adjunctive Agents:

• Stimulant Laxatives:
  • Bisacodyl: 10-15 mg daily-TID orally with goal of 1 non-forced BM every 1-2 days
  • Bisacodyl suppository: One rectally daily-BID
  • Senna ± docusate: 2-3 tablets BID-TID (maximum 8-12 tablets per day) 1, 4
  • FDA warning for bisacodyl: Should not be used for longer than one week 4

For Opioid-Induced Constipation:

• Methylnaltrexone: 0.15 mg/kg subcutaneously every other day (no more than once daily)
  • Contraindicated in post-operative ileus and mechanical bowel obstruction 1, 2

Management Based on Severity

For Fecal Impaction:

1. Disimpaction interventions:

   • Glycerine suppository ± mineral oil retention enema
   • Manual disimpaction (with pre-medication using analgesic ± anxiolytic)
   • Tap water enema until clear 1, 2

2. After disimpaction:

   • Implement maintenance bowel regimen immediately
   • Consider prokinetic agent (e.g., metoclopramide, 10-20 mg PO QID) 1, 2

For Dying Patients (Weeks to Days):

• Increase dose of laxative ± stool softener (senna ± docusate, 2-3 tablets BID-TID)
• Goal remains 1 non-forced BM every 1-2 days 1

Treatment Algorithm

1. Start with: Increased fluids + dietary fiber + exercise + prophylactic medications
2. If inadequate response: Add osmotic laxative (PEG preferred)
3. If still inadequate: Add stimulant laxative
4. For impaction: Suppositories/enemas → manual disimpaction if needed
5. For opioid-induced constipation: Consider methylnaltrexone if standard laxatives fail

Common Pitfalls to Avoid

• Undertreatment: Relying solely on stool softeners without stimulants or osmotic agents
• Inadequate maintenance: Failing to continue preventive regimen after resolution
• Missing proximal impaction: Check for impaction even with diarrhea symptoms
• Prolonged stimulant use: Can lead to dependence and electrolyte imbalances
• Bulk laxatives: Avoid psyllium/Metamucil for opioid-induced constipation 1, 2

The goal of treatment should be one non-forced bowel movement every 1-2 days, with regular monitoring of stool frequency, consistency, and abdominal comfort to evaluate treatment success 1, 2.