Causes of constipation Cancer or cancer-related causes: colorectal cancer, dehydration, intestinal radiation, tumour compression of large intestine Endocrine causes: hormonal changes, hypothyroidism, diabetes, hyperparathyroidism Gastrointestinal disorders: diverticulosis, Hirschsprung disease, irritable bowel syndrome, megacolon, pelvic floor dysfunction, rectoceles, strictures Metabolic causes: hypercalcemia, hypocalcemia, hypokalemia, hypomagnesemia, hypopituitarism, panhypopituitarism, uremia Neurologic causes: autonomic neuropathy, dementia, multiple sclerosis, muscular dystrophies, pain secondary to anal fissures or hemorrhoids, Parkinson disease, spinal cord lesions, stroke Psychological causes: anxiety, depression, eating disorders Other causes: older age, chronic kidney disease, pregnancy, systemic sclerosis, sexual abuse, lack of privacy or time

Data from Fleming and Wade,² Bharucha et al,¹¹ and Andrews and Storr.¹²