What are the current recommendations for managing constipation?

Current Recommendations for Managing Constipation: 2023 AGA-ACG Clinical Practice Guideline

Polyethylene glycol (PEG) is strongly recommended as the first-line pharmacological treatment for chronic idiopathic constipation (CIC) in adults due to its proven efficacy and moderate certainty of evidence. 1

Chronic idiopathic constipation (CIC) affects approximately 8-12% of the US population and can significantly impact quality of life, with medical costs estimated between $2,000-$7,500 per patient annually. The 2023 American Gastroenterological Association (AGA) and American College of Gastroenterology (ACG) joint clinical practice guideline provides evidence-based recommendations for managing this common condition.

Initial Management Approach

Non-Pharmacological Interventions

• Begin with lifestyle modifications including increased fluid intake, increased dietary fiber, and regular exercise 1
• For mild constipation, a trial of fiber supplement should be considered before or in combination with other treatments 1
• Patients with low fluid intake should focus on increasing daily fluid consumption 1

First-Line Pharmacological Treatment

• PEG (polyethylene glycol): Strong recommendation with moderate certainty of evidence 1
  • Dosage: 17g dissolved in 8 ounces of liquid once daily 1
  • Increases complete spontaneous bowel movements (CSBMs) by approximately 2.9 per week compared to placebo 1
  • Response has been shown to be durable over 6 months 1
  • Side effects include abdominal distension, loose stool, flatulence, and nausea 1

Fiber Supplementation

• Conditional recommendation for fiber supplementation in CIC 1
• Different types of fiber have varying effects:
  • Psyllium has the best evidence for efficacy though still low quality 1
  • Wheat bran and psyllium increase stool weight more than inulin 1
  • Finely ground wheat bran can decrease stool water content and harden stool 1
• Common side effect is flatulence 1
• Fiber should be slowly increased over several weeks to minimize adverse effects 2
• Most beneficial for patients with mild-to-moderate symptoms, especially those with diets deficient in fiber 1

Subsequent Treatment Options

Osmotic Laxatives

• After fiber, osmotic laxatives like PEG are recommended 2, 3
• Lactulose is a conditional recommendation for CIC 1

Stimulant Laxatives

• Senna and sodium picosulfate are recommended options 1
• For opioid-induced constipation specifically, a stimulant laxative with or without a stool softener is recommended 1

Stool Softeners

• Docusate sodium can be used after osmotic laxatives 2
• Evidence suggests that adding docusate to sennosides may be less effective than the laxative alone 1

Prescription Medications

• For patients who don't respond to over-the-counter options, the following are strongly recommended:
  • Linaclotide: 145 mcg orally once daily (72 mcg may be used based on individual presentation or tolerability) 1, 4
  • Plecanatide: Strong recommendation 1
  • Prucalopride: Strong recommendation 1, 5
  • Lubiprostone: Conditional recommendation 1, 2

Special Considerations

Diagnostic Testing

• Anorectal tests should be performed in patients who don't respond to over-the-counter agents to evaluate for defecatory disorders 3
• Colonic transit testing may be necessary to identify colonic dysmotility in refractory cases 3

Refractory Constipation

• For opioid-induced constipation that persists despite laxative therapy, methylnaltrexone (a peripherally acting μ-opioid antagonist) can be considered 1, 2
• In rare cases of severe slow-transit constipation, colectomy may be necessary 3, 6

Common Pitfalls to Avoid

• Failing to rule out secondary causes of constipation before treating as primary/idiopathic 6
• Not recognizing defecatory disorders, which are present in approximately two-thirds of adult patients with chronic constipation 6
• Long-term use of magnesium-based laxatives should be avoided due to potential toxicity 2
• Treating constipation based solely on stool frequency without addressing other symptoms like straining, incomplete evacuation, and hard stool consistency 3
• Inadequate trial periods for treatments before moving to more aggressive options 1

The management of constipation should follow a stepwise approach, starting with lifestyle modifications and fiber supplementation, followed by osmotic laxatives like PEG, and then progressing to prescription medications for refractory cases, with appropriate diagnostic testing to guide therapy.