Table 3.

Etiology of constipation

Category	Cause
Abnormal motility	Slow-transit constipation, irritable bowel syndrome
Anatomic disorders	Anal fissure, hemorrhoids, rectal polyps, rectocele, rectal stenosis, fistulas, colonic or rectal neoplasm
Drugs	Calcium, iron, opioids, anticonvulsants, antipsychotics, antihistamines
Neurologic	Hirschsprung disease, spinal cord injury, multiple sclerosis, diabetes mellitus, Parkinson disease
Endocrine	Hypothyroidism, pregnancy, hypercalcemia, diabetes mellitus
Psychosocial	Depression, anxiety
Systemic	Scleroderma, amyloidosis, lupus