Constipation

• Primary (functional) causes: Slow transit constipation: Delayed colonic motility.
  Defecatory disorders: Dysfunction of pelvic floor muscles or anal sphincter (e.g., dyssynergia).
• Secondary causes: Diet: Low fiber intake, inadequate fluids. Medications: Opioids, anticholinergics, calcium channel blockers. Metabolic/endocrine: Hypothyroidism, diabetes, hypercalcemia. Neurological: Parkinson’s disease, spinal cord injury.
• Pathophysiology: Involves altered colonic motility, reduced stool water content, and/or impaired rectal evacuation.

Common symptoms: Straining during defecation. Lumpy or hard stools. Sensation of incomplete evacuation. Abdominal bloating or discomfort.

Red-flag symptoms: Unintended weight loss. Rectal bleeding or anemia. Acute onset in older adults. Family history of colorectal cancer or inflammatory bowel disease.

Clinical assessment: Detailed history (bowel habits, diet, medications), physical exam (abdominal, digital rectal exam).

Diagnostic criteria: Rome IV criteria for functional constipation.

Additional testing (if indicated): Blood tests (thyroid function, calcium, glucose).
Colonoscopy (if red flags present). Anorectal manometry, balloon expulsion test (for defecatory disorders). Colonic transit study (e.g., radiopaque markers).

• Non-pharmacological:
  • Dietary modifications: Increased fiber and fluid intake.
    Regular physical activity.
    Bowel training (scheduled toilet visits).
• Pharmacological:
  • Fiber supplements (e.g., psyllium).
    Osmotic laxatives (e.g., polyethylene glycol, lactulose).
    Stimulant laxatives (e.g., bisacodyl, senna) for short-term use.
    Prokinetic agents or secretagogues (e.g., lubiprostone, linaclotide) for chronic cases.
• Biofeedback therapy:
  • For dyssynergic defecation.

• Fecal impaction: May lead to obstructive symptoms or overflow diarrhea.
• Hemorrhoids or anal fissures: Due to straining. Rectal prolapse.
• Reduced quality of life: Chronic abdominal pain, social distress.

• Prevention: High-fiber diet, adequate hydration, and regular exercise. Avoidance of constipating medications when possible.
• Follow-up: Monitor response to dietary and lifestyle changes. Adjust laxative therapy as needed; avoid long-term stimulant use. Reevaluate if symptoms persist or worsen despite intervention.