Typically a complication of chronic constipation that results in the accumulation hardened<unk>  matter in the colon or rectum that cannot be spontaneously evacuated
Elderly and young age
Chronic constipation
Lifestyle factors (immobility, low fiber diet, dehydration)
Medications that impair GI motility (anticholinergics, antipsychotics, opioids)
Anatomic abnormalities (malignancy, anorectal disease, Hirschsprung's disease)
Neurologic conditions (dementia, spinal cord injury, cerebral palsy)
Fecal impaction
Behavioral-related
Rectal foreign body
Lack of exercise
Volvulus 
Diet-related
Volvulus
Clogged G-tube