What are the treatment options for constipation?

Treatment of Constipation

Start with a stimulant laxative (senna 10-15 mg or bisacodyl 10-15 mg, 2-3 times daily) as first-line therapy, aiming for one non-forced bowel movement every 1-2 days. 1

Initial Assessment

Before initiating treatment, rule out the following conditions:

• Fecal impaction - perform digital rectal examination (DRE) to assess for rectal loading 2, 1
• Bowel obstruction - consider plain abdominal X-ray if clinically suspected 2
• Metabolic causes - check corrected calcium levels (hypercalcemia), potassium (hypokalemia), thyroid function (hypothyroidism), and assess for diabetes mellitus 2, 1
• Medication review - identify and withdraw constipating medications when possible 2

Stepwise Treatment Algorithm

First-Line: Stimulant Laxatives

• Senna or bisacodyl 10-15 mg, 2-3 times daily 1
• Do not add stool softeners (docusate) to stimulant laxatives - evidence shows no additional benefit 1
• Goal is one non-forced bowel movement every 1-2 days, not necessarily daily 1

Second-Line: Add Osmotic or Additional Stimulant Laxatives

If constipation persists after first-line therapy, add one of the following 2, 1:

• Polyethylene glycol (PEG) - preferred in elderly patients due to good safety profile 2
• Lactulose 2
• Magnesium hydroxide or magnesium citrate - use cautiously in renal impairment due to hypermagnesemia risk 2
• Rectal bisacodyl 1

Third-Line: Prokinetic Agents

• Metoclopramide 10-20 mg, 2-3 times daily if gastroparesis is suspected 1

Fourth-Line: Secretagogues

For persistent constipation unresponsive to standard laxatives 1:

• Linaclotide
• Lubiprostone
• Plecanatide

Special Situations

Opioid-Induced Constipation

• All patients on opioids should receive prophylactic laxatives unless contraindicated by pre-existing diarrhea 2
• Osmotic or stimulant laxatives are preferred first-line 2
• Avoid bulk laxatives (psyllium) - not recommended for opioid-induced constipation 2
• Consider peripheral opioid antagonists (PAMORAs) such as methylnaltrexone or naloxegol for unresolved cases 2
• Combined opioid/naloxone preparations reduce risk of opioid-induced constipation 2

Fecal Impaction

• Digital fragmentation and extraction followed by water or oil retention enema 2
• Suppositories and enemas are first-line when DRE identifies full rectum or impaction 2
• Implement maintenance bowel regimen after disimpaction to prevent recurrence 2

Enemas are contraindicated in patients with 2:

• Neutropenia or thrombocytopenia
• Paralytic ileus or intestinal obstruction
• Recent colorectal or gynecological surgery
• Recent anal or rectal trauma
• Severe colitis, abdominal inflammation or infection
• Toxic megacolon
• Undiagnosed abdominal pain
• Recent pelvic radiotherapy

Elderly Patients

• Ensure toilet access, especially with decreased mobility 2
• PEG 17 g/day offers efficacious and tolerable solution with good safety profile 2
• Avoid liquid paraffin in bed-bound patients or those with swallowing disorders due to aspiration pneumonia risk 2
• Use saline laxatives (magnesium hydroxide) cautiously due to hypermagnesemia risk 2
• Avoid bulk agents in non-ambulatory patients with low fluid intake due to mechanical obstruction risk 2
• Isotonic saline enemas preferred over sodium phosphate enemas in elderly 2
• Educate patients to attempt defecation twice daily, 30 minutes after meals, straining no more than 5 minutes 2

Adjunctive Measures

Lifestyle Modifications

• Increase fluid intake 2
• Increase physical activity and mobility within patient limits (even bed to chair transfers) 2
• Ensure privacy and comfort for normal defecation 2
• Positioning aids - small footstool to assist gravity and facilitate pressure 2
• Abdominal massage may reduce gastrointestinal symptoms, particularly in patients with neurogenic problems 2

Dietary Fiber

• Consider dietary fiber only if adequate fluid intake (at least 2 liters daily) 1
• Supplemental medicinal fiber (psyllium) is ineffective for medication-induced constipation 1, 3
• Fiber requires doses >10 g/day and treatment duration ≥4 weeks to be effective 4
• Psyllium and pectin are the most effective fiber types when appropriate 4
• Water-insoluble fibers (cellulose, hemicellulose from wheat bran and vegetables) are most effective for laxation 5

Critical Pitfalls to Avoid

• Do not rely on fiber supplements alone - ineffective for medication-induced constipation without adequate hydration 1
• Do not add stool softeners to stimulant laxatives - no additional benefit demonstrated 1
• Reassess for impaction or obstruction if constipation persists despite treatment 1
• Monitor for hypermagnesemia when using magnesium-containing laxatives, especially in renal impairment or elderly patients 2
• Avoid bulk laxatives in non-ambulatory patients with low fluid intake 2