What are the recommended treatments for managing constipation?

Constipation Management

First-Line Treatment: Polyethylene Glycol

Start with polyethylene glycol (PEG) 17g dissolved in 8 ounces of liquid once daily as the first-line pharmacological treatment for chronic constipation in adults, combined with lifestyle modifications. 1, 2, 3

PEG has the strongest evidence base, increasing complete spontaneous bowel movements by approximately 2.9 per week compared to placebo, with durable response over 6 months. 2 Common side effects include abdominal distension, loose stool, flatulence, and nausea. 2

Essential Lifestyle Modifications (Implement Concurrently)

• Fluid intake: Ensure at least 1.5 liters of water daily, increased during exercise, hot weather, or illness 3
• Timing of defecation: Establish regular attempts at defecation 30 minutes after meals to utilize the gastrocolic reflex 1, 3
• Privacy and positioning: Ensure privacy and comfort; use a small footstool to assist gravity and allow easier pressure exertion 1
• Physical activity: Increase mobility within patient limits, even bed-to-chair transfers 1
• Medication review: Discontinue or substitute constipating medications before extensive workup 3

Fiber Supplementation (Mild Symptoms or Adjunctive)

Use fiber supplementation for mild-to-moderate constipation, particularly in patients with fiber-deficient diets. 2 Psyllium has the best evidence among fiber types. 2 Increase fiber intake slowly over several weeks to minimize flatulence and bloating. 4, 5

Avoid bulk laxatives in non-ambulatory patients with low fluid intake due to mechanical obstruction risk. 1

Second-Line Options (If PEG Inadequate)

Osmotic Laxatives

• Lactulose: Conditional recommendation as alternative osmotic agent 1, 2, 3
• Magnesium oxide: Use cautiously; avoid long-term use in renal impairment due to hypermagnesemia risk 1, 4

Stimulant Laxatives

• Sodium picosulfate: Strong recommendation 1
• Bisacodyl or senna: Effective options, though senna has conditional recommendation 1, 2
• Reserve stimulant laxatives for PRN use or when osmotic agents fail 6

Third-Line: Prescription Agents (Refractory Cases)

When over-the-counter options fail:

• Linaclotide: 145 mcg or 290 mcg orally once daily on empty stomach, 30 minutes before meals (strong recommendation) 1, 7
• Plecanatide: Strong recommendation 1, 2
• Prucalopride: Serotonin type 4 agonist with strong recommendation 1, 2
• Lubiprostone: Conditional recommendation 1, 2

Warning: Linaclotide is contraindicated in patients under 2 years due to risk of fatal dehydration. 7

Special Populations

Opioid-Induced Constipation

• Prophylactic laxatives mandatory: All patients on opioids should receive concomitant osmotic or stimulant laxatives unless pre-existing diarrhea exists 1, 3
• Avoid bulk laxatives (psyllium) for opioid-induced constipation 1
• Combined opioid/naloxone preparations reduce constipation risk 1
• Methylnaltrexone (0.15 mg/kg subcutaneously): For refractory opioid-induced constipation despite laxative therapy 1, 3

Elderly Patients

• PEG 17g daily preferred due to efficacy and excellent safety profile 1, 3
• Avoid liquid paraffin in bed-bound patients or those with swallowing disorders (aspiration lipoid pneumonia risk) 1, 3
• Monitor electrolytes when using diuretics or cardiac glycosides concurrently (dehydration/electrolyte imbalance risk) 1
• Isotonic saline enemas preferred over sodium phosphate enemas due to adverse effect profile 1
• Educate patients to attempt defecation twice daily, 30 minutes after meals, straining no more than 5 minutes 1

Management of Fecal Impaction

When digital rectal exam identifies full rectum or impaction:

• Suppositories and enemas are first-line therapy 1
• Disimpaction through digital fragmentation and extraction (if no perforation/bleeding suspected), followed by maintenance bowel regimen 1
• Contraindications to enemas: Neutropenia, thrombocytopenia, paralytic ileus, intestinal obstruction, recent colorectal/gynecological surgery, recent anal/rectal trauma, severe colitis, toxic megacolon, undiagnosed abdominal pain, recent pelvic radiotherapy 1

Adjunctive Therapies

• Abdominal massage: May reduce gastrointestinal symptoms and improve bowel efficiency, particularly in patients with neurogenic problems 1
• Biofeedback therapy: Treatment of choice for defecatory disorders (pelvic floor dysfunction), improving symptoms in >70% of patients 3

Red Flags Requiring Further Investigation

Pursue extensive evaluation for:

• Severe symptoms 1
• Sudden changes in bowel movement number/consistency 1
• Blood in stool 1
• Older adults relative to health status and disease stage 1
• Plain abdominal X-ray may help assess fecal loading and exclude obstruction 1