How is constipation managed in patients with Amyotrophic Lateral Sclerosis (ALS)?

Management of Constipation in Patients with Amyotrophic Lateral Sclerosis (ALS)

In patients with ALS, constipation should be managed with a combination of dietary fiber supplementation, adequate fluid intake, and stimulating laxatives, with escalation to more advanced therapies for refractory cases. 1

Prevalence and Pathophysiology

Constipation is a common non-motor symptom in ALS patients:

• Affects up to 52.9% of patients after median follow-up of 18 months 2
• More prevalent in patients with impaired motor function 2
• Associated with enteral nutrition (3.69 times higher risk) 2
• Results from:
  • Delayed colonic transit times 3
  • Decreased physical activity
  • Possible autonomic nervous system involvement 3
  • Medication side effects

Assessment and Evaluation

• Assess for treatable causes:
  • Hypercalcemia
  • Hypokalemia
  • Hypothyroidism
  • Diabetes mellitus
  • Medication side effects 1
• Rule out impaction or obstruction 1
• Evaluate severity based on frequency, consistency, and associated symptoms

First-Line Management

1. Dietary Modifications:

   • Add dietary fiber for patients with adequate fluid intake 1
   • Increase fluid intake 1
   • Consider fractionating meals in patients with muscular fatigue 1

2. Stimulating Laxatives:

   • Bisacodyl 10-15 mg, 2-3 times daily 1
   • Target goal: 1 non-forced bowel movement every 1-2 days 1
   • Senna can be used as an effective stimulant laxative 1

Second-Line Management (For Persistent Constipation)

If constipation persists despite first-line measures:

1. Additional Laxative Options:

   • Rectal bisacodyl once daily 1
   • Oral polyethylene glycol 1
   • Lactulose 1
   • Magnesium hydroxide or magnesium citrate 1

2. For Impaction:

   • Glycerin suppositories 1
   • Manual disimpaction if necessary 1

3. For Suspected Gastroparesis:

   • Consider adding metoclopramide as a prokinetic agent 1

Advanced Management (For Refractory Cases)

For constipation not responding to standard therapies:

1. For Opioid-Induced Constipation:

   • Methylnaltrexone 0.15 mg/kg every other day (no more than once daily) 1
   • Contraindicated in patients with postoperative ileus or mechanical bowel obstruction 1
   • Naloxegol may be considered for chronic opioid users 1

2. Other Advanced Options:

   • Lubiprostone (activates chloride channels to enhance intestinal fluid secretion) 1
   • Linaclotide (agonist of guanylate cyclase-C receptors) 1
   • Consider neostigmine for severe cases resembling acute colonic pseudo-obstruction 4

3. Probiotics:

   • Fermented milk containing probiotics and prebiotic fiber has shown benefit in improving bowel movements in neurological conditions 1

Special Considerations

• Enteral Nutrition: Patients receiving enteral nutrition require special attention as they have significantly higher risk of constipation 2
• Medication Review: Assess for medications that may worsen constipation (especially anticholinergics) 5
• Progressive Disease: Constipation management needs may change as ALS progresses and mobility decreases 2

Monitoring and Follow-up

• Regular assessment of bowel movement frequency and consistency
• Evaluate for complications such as impaction, hemorrhoids, or anal fissures
• Adjust management approach as disease progresses and mobility decreases

By implementing this systematic approach to constipation management in ALS patients, clinicians can significantly improve quality of life and prevent complications associated with this common but often undertreated symptom.