What is the treatment for constipation?

Treatment of Constipation

The treatment of constipation should begin with lifestyle modifications including increased fluid intake, physical activity, and dietary fiber, followed by osmotic or stimulant laxatives if needed, with specialized approaches for opioid-induced constipation. 1

Assessment and Diagnosis

• All patients with constipation should be evaluated to determine possible causes, including medication review, physical examination with abdominal assessment, perineal inspection, and digital rectal examination 1
• Rule out impaction, obstruction, and other treatable causes such as hypercalcemia, hypokalemia, hypothyroidism, and diabetes mellitus 1
• Investigations are not routinely necessary, but calcium levels and thyroid function may be checked if clinically indicated 1
• Plain abdominal X-ray may be useful to assess fecal loading and exclude bowel obstruction in severe cases 1

First-Line Management: Lifestyle Modifications

• Ensure privacy and comfort during defecation, with proper positioning (using a small footstool to assist gravity) 1, 2
• Increase fluid intake to maintain proper hydration, as dehydration can worsen constipation 1, 3
• Increase physical activity within patient limits, even bed to chair movement for limited mobility patients 1, 2
• Increase dietary fiber intake when appropriate, aiming for 25-50 grams daily 1, 4
• Consider abdominal massage to help reduce gastrointestinal symptoms, particularly in patients with neurogenic problems 1

Pharmacological Management

First-Line Medications

• Osmotic laxatives are preferred first-line options:

  • Polyethylene glycol (PEG) produces bowel movements within 1-3 days 1, 5
  • Lactulose or magnesium salts (use cautiously with renal impairment) 1

• Stimulant laxatives are also effective first-line options:

  • Senna, cascara, bisacodyl, or sodium picosulfate 1
  • For opioid-induced constipation, prophylactic stimulant laxatives should be prescribed 1

Important Medication Considerations

• Bulk laxatives such as psyllium are not recommended for opioid-induced constipation 1
• Stool softeners like docusate may be less effective than stimulant laxatives alone 1, 6
• Aim for one non-forced bowel movement every 1-2 days 1

Management of Persistent Constipation

• If constipation persists despite first-line treatment:

  • Reassess for bowel obstruction or impaction 1
  • Add or switch to different laxatives (e.g., add bisacodyl 10-15 mg 2-3 times daily) 1
  • Consider prokinetic agents such as metoclopramide for persistent constipation, though long-term use may cause neurologic complications 1

• For fecal impaction:

  • Use glycerin suppositories or perform manual disimpaction 1, 2
  • Follow with maintenance bowel regimen to prevent recurrence 1
  • Suppositories and enemas are preferred when digital rectal examination identifies a full rectum 1

Special Considerations

Opioid-Induced Constipation (OIC)

• All patients receiving opioid analgesics should receive prophylactic laxative therapy unless contraindicated by pre-existing diarrhea 1
• For refractory OIC, consider:
  • Peripherally acting μ-opioid receptor antagonists (PAMORAs) like methylnaltrexone at 0.15 mg/kg every other day 1
  • Combined opioid/naloxone medications 1
  • Opioid rotation to fentanyl or methadone 1

Elderly Patients

• Pay particular attention to assessment of elderly patients 1
• Ensure access to toilets, especially with decreased mobility 1, 2
• Provide dietetic support and manage decreased food intake 1
• Review and discontinue unnecessary constipating medications 1

Contraindications and Cautions

• Enemas are contraindicated in patients with neutropenia, thrombocytopenia, paralytic ileus, intestinal obstruction, recent colorectal or gynecological surgery, recent anal or rectal trauma, severe colitis, toxic megacolon, undiagnosed abdominal pain, or recent pelvic radiotherapy 1, 2
• Magnesium and sulfate salts should be used cautiously in renal impairment due to risk of hypermagnesemia 1
• Contrary to common belief, chronic use of stimulant laxatives at recommended doses is not harmful to the colon 7