What is the treatment of choice for straining with constipation?

Treatment of Choice for Straining with Constipation

For straining with constipation, fiber supplementation and/or osmotic laxatives (particularly polyethylene glycol) are the first-line treatments, with stimulant laxatives as effective alternatives, while biofeedback therapy is strongly recommended for defecatory disorders causing straining. 1

Initial Assessment and Classification

When evaluating straining with constipation, it's important to determine the underlying cause:

1. Normal Transit Constipation (NTC): Normal colonic transit time but difficulty with evacuation
2. Slow Transit Constipation (STC): Delayed colonic transit
3. Defecatory Disorder: Dysfunction of pelvic floor muscles during attempted defecation

Straining is particularly common in defecatory disorders, where patients have difficulty coordinating abdominal, rectal, and pelvic floor muscles during defecation.

First-Line Treatment Algorithm

Step 1: Lifestyle and Dietary Modifications

• Increase fluid intake
• Regular physical activity if feasible
• Optimize toileting habits: attempt defecation 30 minutes after meals, strain no more than 5 minutes 1

Step 2: First-Line Pharmacologic Treatment

• Fiber supplementation: 15g of psyllium daily 1

  • Caution: Avoid bulk laxatives in patients with opioid-induced constipation 2 or non-ambulatory patients with low fluid intake 1

• Osmotic laxatives:

  • Polyethylene glycol (PEG): 17g daily (preferred option) 1
  • Milk of magnesia: 1 oz twice daily (avoid in renal impairment) 1

• Stimulant laxatives:

  • Bisacodyl: 10-15mg daily 1, 2
  • Senna: 2 tablets daily (can increase to 8-12 tablets per day) 2
  • Glycerol suppositories: preferably administered 30 minutes after meals 1

Treatment for Specific Types of Constipation

For Defecatory Disorders (with straining)

• Biofeedback therapy is strongly recommended over laxatives (high-quality evidence) 1
  • Success rate: >70% improvement in symptoms 1
  • Teaches patients to relax pelvic floor muscles during straining
  • Correlates relaxation and pushing to achieve defecation

For Opioid-Induced Constipation with Straining

1. Stimulant laxatives (senna or bisacodyl) as first-line 2
2. PEG as an effective alternative 2
3. For refractory cases, peripherally acting μ-opioid receptor antagonists (PAMORAs) 2
   • Naldemedine: 0.2mg daily
   • Naloxegol: 25mg once daily

For Elderly Patients with Constipation

• PEG (17 g/day) is preferred due to good safety profile 1
• Avoid liquid paraffin in bed-bound patients (risk of aspiration) 1
• Consider rectal measures (suppositories, enemas) for swallowing difficulties 1

Management of Refractory Constipation

If initial treatments fail:

1. Perform anorectal testing to identify defecatory disorders (strong recommendation, high-quality evidence) 1
2. Consider newer agents for normal or slow transit constipation 1
   • Lubiprostone
   • Linaclotide
3. For severe cases unresponsive to all treatments:
   • Consider surgical options (only in ~5% of cases) 1
   • Total colectomy with ileorectal anastomosis for documented STC 1

Common Pitfalls to Avoid

• Don't rely on bulk laxatives alone for opioid-induced constipation 2
• Don't delay biofeedback therapy for patients with defecatory disorders 1
• Don't use saline laxatives (e.g., magnesium hydroxide) in elderly patients or those with renal impairment 1
• Don't use enemas in patients with neutropenia, thrombocytopenia, recent colorectal surgery, or severe colitis 1
• Don't continue ineffective treatments - if no response to initial measures, perform diagnostic testing to understand underlying pathophysiology 3

By following this algorithm and matching treatment to the underlying cause of straining with constipation, most patients can achieve significant symptom improvement and better quality of life.