Skip to content

Approach to Chronic Constipation 📋

Introduction 🏥

Chronic constipation is a common gastrointestinal complaint affecting millions of patients worldwide. It is defined as persistently difficult, infrequent, or seemingly incomplete defecation lasting for at least 3 months1. While most persons have at least three bowel movements per week, the diagnosis of constipation extends beyond frequency alone to include symptoms such as excessive straining, hard stools, lower abdominal fullness, or a sense of incomplete evacuation.

Pathophysiology 🧠

Chronic constipation generally results from: - Inadequate fiber or fluid intake 💧 - Disordered colonic transit - Anorectal dysfunction - Neurogastroenterologic disturbances - Medication side effects 💊 - Systemic diseases affecting the GI tract2

Two major subtypes deserve special attention: 1. Slow transit constipation: Characterized by delayed emptying of the ascending and transverse colon with reduced frequency of high-amplitude propagated contractions (HAPCs) 2. Evacuation disorders (outlet obstruction): Account for approximately 25% of cases in tertiary care settings

Clinical Evaluation 🔍

History Taking

A comprehensive history should explore: - Frequency: Fewer than three bowel movements per week - Consistency: Lumpy or hard stools (Bristol Stool Scale) - Associated symptoms: - Excessive straining - Prolonged defecation time - Need to support the perineum - Digital manipulation of the anorectum - Sense of incomplete evacuation3

Red Flags 🚨

Recent onset constipation may indicate: - Colorectal malignancy - Anorectal strictures - Inflammatory conditions

Physical Examination

Mandatory components include: - General physical examination - Abdominal examination - Digital rectal examination (DRE) - crucial for: - Excluding fecal impaction - Assessing anal sphincter tone - Evaluating perineal descent - Identifying paradoxical puborectalis contraction4

Diagnostic Approach 🔬

Initial Management

In >90% of cases, there is no underlying organic cause, and constipation responds to: - Adequate hydration 💦 - Regular exercise 🏃‍♂️ - Dietary fiber supplementation (15-25 g/day) - Medication review (identify constipating drugs) - Attention to psychosocial factors5

Investigation Algorithm

For severe or refractory constipation (<5% of patients):

1. Basic Laboratory Tests
   - Complete blood count
   - Thyroid function tests
   - Electrolytes, calcium
   - Chest and abdominal X-ray

2. Exclude Mechanical Obstruction
   - Colonoscopy (preferred >40 years)
   - Barium enema (alternative)

3. Specialized Testing
   - Colonic transit study
   - Anorectal manometry
   - Balloon expulsion test
   - Defecography (if indicated)

Special Tests for Evacuation Disorders 🎯

  • Simple office test: Ask patient to strain and expel examiner's finger during DRE
  • Anorectal manometry: Evaluates sphincter function and rectoanal reflexes
  • Balloon expulsion test: Assesses ability to evacuate
  • Defecography: Visualizes anatomical abnormalities during defecation

Management Strategy 💊

First-Line Therapy

  1. Lifestyle modifications
  2. Bulk-forming laxatives (psyllium, methylcellulose)
  3. Osmotic laxatives (polyethylene glycol, lactulose)

Second-Line Therapy

  1. Stimulant laxatives (senna, bisacodyl)
  2. Secretagogues:
  3. Lubiprostone (chloride channel activator)
  4. Linaclotide (guanylate cyclase C agonist)6

Management of Evacuation Disorders

  • Biofeedback therapy: First-line treatment with 70-80% success rate
  • Pelvic floor rehabilitation
  • Surgery: Reserved for specific anatomical abnormalities

Special Considerations 🤔

Psychological Factors

Formal evaluation may identify: - Eating disorders - Depression - Control issues - Post-traumatic stress disorders

These conditions may benefit from cognitive behavioral therapy or psychiatric intervention.

Hospitalized Patients

Constipation often worsens during hospitalization due to: - Physical immobility - Medication changes - Dietary alterations - Environmental factors

Conclusion 📝

The approach to chronic constipation requires a systematic evaluation beginning with a thorough history and physical examination. While most cases respond to conservative measures, a subset of patients with severe or refractory symptoms require specialized testing to identify slow transit constipation or evacuation disorders. The management strategy should be individualized based on the underlying pathophysiology, with attention to both physical and psychological factors affecting bowel function.

  1. Harrison's Principles of Internal Medicine, 21st Edition, Chapter 46: Diarrhea and Constipation ↩

  2. Table 46-5: Causes of Constipation in Adults, Harrison's Principles of Internal Medicine, 21st Edition ↩

  3. The Rome IV criteria provide standardized diagnostic criteria for functional constipation ↩

  4. Digital rectal examination technique and interpretation, Harrison's Chapter 46 ↩

  5. Management algorithm for constipation, Figure 46-5, Harrison's Principles of Internal Medicine ↩

  6. Camilleri M et al: Chronic constipation. Nat Rev Dis Primers 3:17095, 2017 ↩