What are the treatment options for chronic constipation?

Treatment Options for Chronic Constipation

For adults with chronic idiopathic constipation (CIC), a stepwise approach starting with fiber supplementation, particularly psyllium, followed by polyethylene glycol (PEG) is recommended as first-line therapy. 1

First-Line Treatments

Dietary Fiber

• Fiber supplements are suggested as first-line therapy for CIC, especially for individuals with low dietary fiber intake 1
• Among fiber supplements, psyllium has the strongest evidence for effectiveness 1
• Adequate hydration should be encouraged with fiber supplementation 1
• Common side effects include flatulence 1
• A dietary assessment is important to determine total fiber intake from diet and supplements 1

Osmotic Laxatives

• Polyethylene glycol (PEG) is strongly recommended when fiber supplements are insufficient 1
• PEG has shown durable response over 6 months of use 1
• Side effects include abdominal distension, loose stool, flatulence, and nausea 1
• A trial of fiber supplement can be considered for mild constipation before PEG use or in combination with PEG 1

Second-Line Treatments

Stimulant Laxatives

• Stimulant laxatives such as bisacodyl (10-15 mg, 2-3 times daily) can be used when first-line treatments fail 1
• The goal should be one non-forced bowel movement every 1-2 days 1
• For impaction, glycerine suppositories may be administered or manual disimpaction may be performed 1

Prescription Medications

• Lubiprostone is FDA-approved for the treatment of CIC in adults 2
• Linaclotide is effective for CIC, showing improvements in complete spontaneous bowel movements (CSBMs), stool consistency, and reduced straining 3
• Prucalopride (a prokinetic agent) is recommended as a second-line treatment in refractory CIC patients 4

Special Considerations

Opioid-Induced Constipation

• Peripherally acting μ-opioid receptor antagonists like methylnaltrexone (0.15 mg/kg every other day) can help relieve opioid-induced constipation while preserving pain management 1
• Lubiprostone is also indicated for opioid-induced constipation in adult patients with chronic non-cancer pain 2
• Methylnaltrexone should not be used in patients with postoperative ileus or mechanical bowel obstruction 1

Refractory Constipation

• For patients with ano-rectal dyssynergia, pelvic floor rehabilitation is recommended 4
• Secretagogues (linaclotide, plecanatide) and bile acid transporter inhibitors (elobixibat) can be effective in patients not responsive to second-line treatments 4, 5
• Surgical approaches have limited indications in selected cases of inertia coli refractory to other treatments and obstructed defecation 4

Treatment Algorithm

1. Initial approach: Assess dietary fiber intake and recommend fiber supplementation (particularly psyllium) along with adequate hydration 1
2. If inadequate response: Add polyethylene glycol (PEG) 1
3. For persistent symptoms: Consider stimulant laxatives (bisacodyl) 1
4. For refractory cases: Evaluate for rectal evacuation disorders with specialized testing (anorectal manometry, defecography) 6
5. Prescription medications: Consider lubiprostone, linaclotide, or prucalopride based on symptom pattern and response to previous treatments 2, 3, 4

Common Pitfalls and Caveats

• Failure to assess total fiber intake before recommending additional fiber 1
• Not ensuring adequate hydration when increasing fiber intake, which can worsen constipation 1
• Overlooking potential secondary causes of constipation (medications, metabolic disorders, structural abnormalities) 7, 6
• Prolonged use of stimulant laxatives without trying other approaches first 7
• Not recognizing when constipation may be due to pelvic floor dysfunction or evacuation disorders, which require different management approaches 4, 6