What are the recommendations for managing constipation?

Management of Constipation

For the management of constipation, polyethylene glycol (PEG) is strongly recommended as a first-line pharmacological treatment due to its proven efficacy and favorable safety profile. 1, 2

Assessment and Diagnosis

• All patients should be evaluated for constipation with questions to determine possible causes 1
• Physical examination should include:
  • Abdominal examination
  • Perineal inspection
  • Digital rectal examination (DRE) to assess for fecal impaction 1
• Investigations are not routinely necessary unless there are concerning features such as:
  • Severe symptoms
  • Sudden changes in bowel movements
  • Blood in stool
  • Older adults with health concerns 1
• Consider checking calcium levels and thyroid function if clinically suspected 1
• Plain abdominal X-ray may be useful to assess fecal loading and exclude bowel obstruction 1

Treatment Algorithm

Step 1: Non-Pharmacological Interventions

• Dietary modifications:

  • Increase dietary fiber intake to 14g per 1,000 kcal daily 2
  • Ensure adequate fluid intake 1, 2
  • Dietary assessment is important to determine total fiber intake from diet and supplements 1

• Lifestyle modifications:

  • Increase physical activity and mobility within patient limits 1
  • Ensure privacy and comfort for defecation 1
  • Optimize positioning (using a small footstool to assist gravity) 1
  • Abdominal massage may help reduce gastrointestinal symptoms, particularly in patients with neurogenic problems 1

Step 2: Fiber Supplementation

• Psyllium is the most effective fiber supplement and should be used as first-line therapy for mild constipation 1, 2, 3
• Start with a low dose and gradually increase to avoid bloating and flatulence
• Ensure adequate hydration with fiber supplementation 1, 2
• Avoid bulk laxatives in patients with opioid-induced constipation (OIC) 1

Step 3: Osmotic Laxatives

• Polyethylene glycol (PEG) is strongly recommended with moderate certainty of evidence 1, 2

  • Initial dose: 17g daily dissolved in 4-8 ounces (120-240ml) of liquid 2
  • Adjust dose according to response
  • May be used in combination with fiber supplements 1
  • Side effects include abdominal distension, loose stool, flatulence, and nausea 1, 2
  • Do not use for longer than 1 week without medical supervision 4

• Alternative osmotic laxatives:

  • Lactulose
  • Magnesium salts (use cautiously in renal impairment due to risk of hypermagnesemia) 1

Step 4: Stimulant Laxatives

• Consider when osmotic laxatives are insufficient:
  • Senna
  • Bisacodyl
  • Sodium picosulfate 1
• Do not use for longer than one week unless directed by a doctor 5
• Stop use and consult a doctor if rectal bleeding occurs or if there is no bowel movement after use 5

Step 5: Prescription Medications for Refractory Cases

• Prucalopride is recommended for chronic idiopathic constipation (CIC) not responding to over-the-counter agents 1
  • Duration of treatment in trials was 4-24 weeks, with no limit provided in drug labeling
  • May cause headache, abdominal pain, nausea, and diarrhea 1

Special Considerations

Opioid-Induced Constipation (OIC)

• Unless contraindicated by pre-existing diarrhea, all patients receiving opioid analgesics should be prescribed a concomitant laxative 1
• Osmotic or stimulant laxatives are generally preferred 1
• Bulk laxatives such as psyllium are not recommended for OIC 1

Fecal Impaction

• In the absence of suspected perforation or bleeding, management involves:
  • Digital fragmentation and extraction of stool
  • Implementation of a maintenance bowel regimen to prevent recurrence 1
• Suppositories and enemas are preferred first-line therapy when DRE identifies a full rectum or fecal impaction 1

Elderly Patients

• Ensure access to toilets, especially for patients with decreased mobility 1
• Provide dietetic support 1
• Optimize toileting: educate patients to attempt defecation at least twice a day (30 min after meals) and strain no more than 5 minutes 1
• PEG (17g/day) offers an efficacious and tolerable solution with good safety profile 1
• Avoid liquid paraffin for bed-bound patients and those with swallowing disorders 1
• Use saline laxatives cautiously due to risk of hypermagnesemia 1
• Avoid non-absorbable, soluble dietary fiber in non-ambulatory patients with low fluid intake 1

Common Pitfalls and Caveats

• Do not use laxatives for longer than one week without medical supervision 4, 5
• Stop use and consult a doctor if rectal bleeding occurs or if abdominal pain worsens 4, 5
• Enemas are contraindicated in patients with:
  • Neutropenia or thrombocytopenia
  • Paralytic ileus or intestinal obstruction
  • Recent colorectal or gynecological surgery
  • Recent anal or rectal trauma
  • Severe colitis, inflammation, or infection of the abdomen
  • Toxic megacolon
  • Undiagnosed abdominal pain
  • Recent pelvic radiotherapy 1