Constipation in Adults - Chronic Functional

Definition

Chronic functional constipation is a common gastrointestinal disorder characterized by infrequent, difficult, or incomplete bowel movements in the absence of any structural or biochemical abnormalities.

Epidemiology

• Affects 12–19% of the global population
• More common in females than males
• Prevalence increases with age, especially >60 years
• Common in patients with low fiber intake, sedentary lifestyle, or certain medications
• Significant impact on quality of life and healthcare costs

Etiology

• Primary (functional) constipation: slow-transit constipation, normal-transit constipation, or outlet obstruction
• Secondary causes: medications (opioids, anticholinergics), metabolic disorders (hypothyroidism, diabetes), neurologic disorders (Parkinson’s, multiple sclerosis), structural anorectal abnormalities
• Lifestyle factors: low fiber intake, dehydration, physical inactivity
• Psychological factors: stress, depression, eating disorders

Pathophysiology

• Impaired colonic motility or slow-transit leading to delayed stool movement
• Pelvic floor dysfunction or dyssynergic defecation causing outlet obstruction
• Altered gut-brain axis and intestinal sensory-motor dysfunction
• Reduced stool frequency and difficulty in stool passage → chronic symptoms
• Neurohormonal and dietary factors contribute to symptom persistence