What are the treatment options for constipation?

Treatment Options for Constipation

The most effective approach to treating constipation begins with lifestyle modifications including increased fluid intake, physical activity, and dietary fiber, followed by laxatives such as stimulants (bisacodyl, senna) or osmotic agents (polyethylene glycol, lactulose) if needed, with specialized medications like methylnaltrexone reserved for refractory cases, particularly opioid-induced constipation. 1

Initial Assessment and Prevention

• Assess for potential causes of constipation including medications (opioids, antacids, anticholinergics, antidepressants, antispasmodics, phenothiazines, haloperidol), metabolic disorders (hypercalcemia, hypokalemia, hypothyroidism, diabetes mellitus), and rule out obstruction or impaction 1
• Implement preventive measures including adequate fluid intake, dietary fiber, and physical activity when appropriate 1
• For patients on opioids, prophylactic laxative therapy should be initiated immediately, as patients do not develop tolerance to opioid-induced constipation 1

First-Line Treatment Options

Lifestyle Modifications

• Ensure privacy and comfort for normal defecation 1
• Increase fluid intake to maintain adequate hydration 1, 2
• Increase physical activity within patient limitations (even bed to chair movement can help) 1, 3
• Increase dietary fiber intake to at least 20-25g daily, with gradual adjustment to avoid side effects like bloating 4
• Consider abdominal massage to improve bowel efficiency, particularly in patients with neurogenic problems 1

Pharmacological Management

• Stimulant laxatives: Senna (2 tablets every morning; maximum 8-12 tablets daily), bisacodyl (10-15 mg, 2-3 times daily) with goal of one non-forced bowel movement every 1-2 days 1
• Osmotic laxatives: Polyethylene glycol (capful in 8 oz water 1-2 times daily), lactulose (30-60 mL daily), magnesium hydroxide (30-60 mL daily), or magnesium citrate 1, 5
• Stool softeners: May be used in combination with stimulant laxatives, though evidence suggests senna alone may be as effective as senna-docusate combination 1

Second-Line Treatment Options

• For persistent constipation, consider adding rectal bisacodyl suppositories or increasing doses of oral laxatives 1
• For impaction, use glycerine suppositories or perform manual disimpaction 1
• If gastroparesis is suspected, consider adding a prokinetic agent such as metoclopramide 1

Treatment for Refractory Constipation

• For opioid-induced constipation unresponsive to standard therapy, consider peripherally acting μ-opioid receptor antagonists:
  • Methylnaltrexone 0.15 mg/kg subcutaneously every other day (no more than once daily) 1
  • Naloxegol for patients receiving chronic opioids for non-cancer pain 1
• For chronic idiopathic constipation or constipation associated with irritable bowel syndrome:
  • Lubiprostone (activates chloride channels to enhance intestinal fluid secretion) 1
  • Linaclotide (agonist of guanylate cyclase-C receptors) 1, 5

Special Considerations

Elderly Patients

• Ensure access to toilets, especially for those with decreased mobility 1
• Provide dietetic support and manage decreased food intake 1
• Optimize toileting habits - attempt defecation 30 minutes after meals, no more than 5 minutes of straining 1
• Polyethylene glycol (17 g/day) is particularly effective and well-tolerated in elderly patients 1, 5
• Avoid liquid paraffin in bed-bound patients or those with swallowing disorders due to aspiration risk 1

Cancer Patients

• Constipation occurs in approximately 50% of patients with advanced cancer 1
• For opioid-induced constipation in cancer patients, prophylactic stimulant laxatives are essential 1
• Consider discontinuing non-essential constipating medications 1
• For refractory cases, methylnaltrexone has shown effectiveness while preserving opioid analgesia 1

Important Caveats

• Bulk laxatives such as psyllium are not recommended for opioid-induced constipation 1, 6
• Magnesium-based laxatives should be used cautiously in patients with renal impairment due to risk of hypermagnesemia 1, 5
• Methylnaltrexone should not be used in patients with postoperative ileus or mechanical bowel obstruction 1
• Laxatives should generally not be used for longer than one week without medical supervision 7, 6
• Seek medical attention if constipation is accompanied by rectal bleeding, severe abdominal pain, or failure to have a bowel movement despite treatment 6, 5