What are the management options for constipation?

Management Options for Constipation

The first-line treatment for constipation is polyethylene glycol (PEG) 3350 at a dosage of 17g dissolved in 8oz of water once daily, which has moderate certainty of evidence for effectiveness and a favorable safety profile. 1

Pharmacological Management

First-Line Options

• Osmotic Laxatives
  • PEG 3350: 17g dissolved in 8oz water once daily; produces bowel movements within 1-3 days; safe for up to 12 months of continuous use 1
  • Lactulose: 15-30ml daily or twice daily as an alternative 1
  • Magnesium-based laxatives: Avoid in patients with renal insufficiency 1

Second-Line Options

• Stimulant Laxatives
  • Senna (8.6-17.2mg) or bisacodyl (5-10mg) at bedtime 1
  • Particularly useful when osmotic laxatives alone are insufficient

For Opioid-Induced Constipation

• Naldemedine: 0.2mg daily (strong evidence for achieving ≥3 spontaneous bowel movements/week) 1
• Naloxegol: Recommended with moderate-quality evidence 1
• Methylnaltrexone: 0.15mg/kg subcutaneously every other day (no more than once daily); useful when oral medications cannot be used 1
• Lubiprostone: 24mcg twice daily with food; use with caution in patients taking methadone 1
• Note: PAMORAs (peripherally acting mu-opioid receptor antagonists) are contraindicated in patients with gastrointestinal perforation risk or mechanical bowel obstruction 1

Novel Agents

• Plecanatide: FDA-approved for chronic idiopathic constipation; acts as a guanylate cyclase-C agonist in the GI tract with minimal systemic absorption 2
  • Clinical trials showed 21% responder rate vs. 10-13% for placebo 2
  • Improvements in stool frequency and consistency observed as early as week 1 2

Lifestyle Modifications

Dietary Changes

• Gradually increase dietary fiber to 20-25g per day, focusing on soluble fiber 1
• Increase fluid intake to at least 8 glasses of water daily 1
• Consider mineral water rich in magnesium and/or bicarbonate 3

Physical Activity

• Increase physical activity within patient limits 1
• Aim for at least 30 minutes of exercise per day to alleviate symptoms 4

Toileting Habits

• Optimize toileting habits:
  • Ensure privacy and comfort
  • Use a footstool to elevate knees above hips
  • Establish a regular toileting schedule 1
  • Ensure access to toilets, especially for patients with decreased mobility 1

Assessment and Monitoring

Initial Evaluation

• Evaluate for red flag symptoms:

  • Rectal bleeding
  • Unintentional weight loss
  • Change in stool caliber
  • Progressive abdominal pain 1

• Physical examination:

  • Abdominal examination
  • Perineal inspection
  • Digital rectal examination to assess for fecal impaction 1

Monitoring Treatment Response

• Reassess treatment efficacy within 2-4 weeks of initiating therapy 1
• Goal: One non-forced bowel movement every 1-2 days 1
• Use the Bowel Function Index to assess severity and monitor response:
  • Score ≥30 indicates clinically significant constipation requiring escalation of therapy 1

Special Situations

Fecal Impaction

• Consider rectal interventions:
  • Glycerine suppositories
  • Rectal bisacodyl twice daily
  • Manual disimpaction if necessary 1

Types of Constipation and Specific Approaches

• Slow Transit Constipation: May require laxative therapy beyond fiber and increased activity 5
• Pelvic Floor Dysfunction/Dyssynergic Defecation: Biofeedback therapy and pelvic muscle re-education 5
• Constipation-predominant IBS: Dietary monitoring and modifications, fiber therapy, and patient education 5

Important Caveats and Pitfalls

• Docusate has not shown benefit and is not recommended 1
• Using fiber supplements in patients with severe constipation or suspected obstruction is not recommended 1
• Continuing ineffective treatments without reassessment is not recommended 1
• Using PAMORAs as first-line treatment is not recommended 1
• Common side effects of PEG include diarrhea, abdominal distension, flatulence, and nausea, which are typically mild to moderate 1
• Bloating and flatulence are common side effects of highly fermentable fibers 4
• Conservative treatment (lifestyle modifications alone) is usually insufficient and should be supplemented with laxatives or motility-enhancing drugs 4