Table 1.

Various pathological and non-pathological conditions that associate constipation as a clinically important aspect.

Functional Causes	Dietary Factors (Low Residue) Motility Disturbance (Slow Transit Time, Irritable Bowel Syndrome) Sedentary Lifestyle
Degeneration of enteric neurons	Chagas disease
Structural abnormalities	Anorectal disorders (anal or perianal fissures, thrombosed hemorrhoids) Colonic strictures (diverticulosis, ischemia, radiation therapy) Colonic tumor and obstruction (adenocarcinoma)
Smooth muscle and connective tissue disorders	Scleroderma, amyloidosis Toxic megacolon—inflammatory bowel disease (ulcerative colitis, Crohn disease, Cytomegalovirus, Salmonella, medications, etc)
Psychogenic conditions	Anxiety, depression, somatization
Neurogenic conditions	Cerebrovascular events, sclerosis, Parkinson’s disease, Hirschsprung’s disease, spinal cord tumors
Endocrine and metabolic conditions	Hypo- and hyperparathyroidism, diabetes mellitus, hypo- and hypercalcemia, uremia
Drugs	Antidepressants, narcotics, psychotropics, sympathomimetics, anticholinergics, diuretics, antacids, non-steroidal anti-inflammatory drugs, calcium channel blockers, etc.