Acute stool retention suggests a physical cause; Chronic stool retention can be somatic and functional.
In atony, the colon does not respond to the usual stimulation of food and physical activity that promote bowel movements, or these stimuli are insufficient. The patient has infrequent bowel movements, but does not feel the need to defecate. Atony usually develops when the sensitivity of the rectum to feces decreases with the usual neglect of the urge to defecate or prolonged use of laxatives or enemas. This usually occurs in older people due to age-related decline in colonic reflexes, low fiber diet, lack of physical activity, and use of medications that cause constipation.
Acute stool retention
- Acute intestinal obstruction
- Volvulus, hernia, adhesions, coprostasis
- Dynamic intestinal obstruction
- Medicines
- Peritonitis, traumatic brain or spinal injury, bed rest
- Anticholinergics (neuroleptics, antiparkinsonians, antispasmodics), cations (iron, Ca, barium, bismuth), opioids, general anesthesia
Chronic stool retention
- Colon tumor
- Metabolic disorders
- CNS disorders
- Peripheral nervous system disorders
- Systemic disorders
- Functional disorders
- Diabetes mellitus, hypothyroidism, hypercalcemia, uremia, porphyria
- Parkinson’s disease, multiple sclerosis, stroke, spinal cord lesions
- Hirschsprung’s disease (aganglionosis), neurofibromatosis, damage to the autonomic nervous system
- Systemic sclerosis, amyloidosis, dermatomyositis, muscular dystrophy
- Colon atony, irritable bowel syndrome
Fecal impaction (“fecal blockage”, fecal stones), which can develop with stool retention, is especially typical for older people. With age, the rectal cavity enlarges and colonic motility decreases, especially with prolonged bed rest or decreased physical activity. This is also observed after oral barium ingestion or during barium enema. The patient experiences rectal pain and tenesmus and makes repeated but futile attempts to defecate. The patient may experience cramping pain and thick masses may be surrounded by watery mucus or liquid stool, resembling diarrhea (paradoxical diarrhea). Examination of the rectum reveals rocky hard stool, but more often putty-like stool.