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, perform a focused evaluation:

• Conduct an abdominal examination, perineal inspection, and digital rectal examination (DRE) to identify fecal impaction or rectal loading 2, 3
• Rule out metabolic causes: Check corrected calcium levels (hypercalcemia), thyroid function (hypothyroidism), potassium levels (hypokalemia), and consider diabetes mellitus 1, 3
• Exclude bowel obstruction or perforation before proceeding with treatment 1, 3
• Plain abdominal X-ray may be useful to visualize the extent of fecal loading and exclude obstruction 2, 3

Stepwise Treatment Algorithm

First-Line: Stimulant Laxatives

• Prescribe senna or bisacodyl 10-15 mg, 2-3 times daily as the initial pharmacologic intervention 1
• Do NOT add stool softeners (docusate) to stimulant laxatives — evidence shows no additional benefit 1
• Avoid bulk laxatives (psyllium, methylcellulose) for medication-induced constipation as they are ineffective without adequate hydration (at least 2 liters daily) 1, 3

Second-Line: Add Osmotic Laxatives

If constipation persists after 3-7 days, add one of the following:

• Polyethylene glycol (PEG) — preferred osmotic agent 2, 1, 3
• Lactulose 2, 1, 3
• Magnesium hydroxide or magnesium citrate — use cautiously in renal impairment due to hypermagnesemia risk 2, 1
• Rectal bisacodyl suppository 1

Third-Line: Prokinetic Agents

• If gastroparesis is suspected, add metoclopramide 10-20 mg, 2-3 times daily 1
• This is particularly relevant for patients on GLP-1 agonists (e.g., Mounjaro) which slow gastric emptying 1

Fourth-Line: Secretagogues

• For persistent constipation unresponsive to standard laxatives, consider linaclotide, lubiprostone, or plecanatide 1

Non-Pharmacological Measures

Implement these alongside pharmacologic therapy:

• Ensure privacy and comfort for defecation 2, 3
• Use positioning aids: A small footstool helps patients exert pressure more easily 2, 3
• Increase fluid intake to at least 2 liters daily 1, 3
• Increase physical activity and mobility within patient limits, even bed-to-chair transfers 2, 3
• Abdominal massage may reduce gastrointestinal symptoms, particularly in patients with neurogenic problems 2, 3
• Dietary fiber should only be considered if fluid intake is adequate (≥2 liters daily); fiber requires at least 4 weeks and doses >10 g/day to be effective 1, 4

Special Situations

Opioid-Induced Constipation

• Prescribe a concomitant laxative prophylactically when initiating opioid therapy, unless contraindicated by pre-existing diarrhea 2, 3
• Use osmotic or stimulant laxatives as first-line 2, 3
• Avoid bulk laxatives (psyllium) for opioid-induced constipation 2
• For refractory cases, consider methylnaltrexone 0.15 mg/kg subcutaneously every 2 days (not to exceed once daily) or other PAMORAs 2, 3

Fecal Impaction

• If DRE identifies a full rectum or fecal impaction, use suppositories and enemas as first-line therapy 2
• Perform digital fragmentation and extraction in the absence of suspected perforation or bleeding, followed by maintenance bowel regimen 2, 3
• Contraindications to enemas include: neutropenia, thrombocytopenia, paralytic ileus, recent colorectal/gynecological surgery, recent anal/rectal trauma, severe colitis, toxic megacolon, undiagnosed abdominal pain, or recent pelvic radiotherapy 2

Elderly Patients

• Ensure access to toilets, especially with decreased mobility 2, 3
• Educate patients to attempt defecation twice daily, 30 minutes after meals, straining no more than 5 minutes 2, 3
• PEG 17 g/day is safe and effective in elderly patients 3
• Avoid liquid paraffin in bedridden patients or those with swallowing disorders due to aspiration risk and lipoid pneumonia 3

Critical Pitfalls to Avoid

• Do not rely on fiber supplements alone — they are ineffective for medication-induced constipation without adequate hydration 1
• Do not add stool softeners to stimulant laxatives — no evidence of benefit 1
• Reassess for impaction or obstruction if constipation persists despite treatment 1
• Discontinue non-essential constipating medications 3
• Monitor for dehydration and electrolyte imbalances when using magnesium salts with diuretics or cardiac glycosides 3

Treatment Goals

Aim for one non-forced bowel movement every 1-2 days, not necessarily daily bowel movements. 1