Overview of constipation in palliative care

Normal frequency of bowel motions varies between individuals and normal defecation requires a number of factors: a diet adequate in fibre and fluid, normal peristalsis, adequate power in the abdominal and pelvic musculature, normal rectal and perianal sensation, and patient mobility. Many of these requirements are not fulfilled in patients approaching the end of life, and constipation becomes almost universal. See the Gastrointestinal guidelines for a definition of constipation.

Constipation is exacerbated by opioids and anticholinergic drugs, which are commonly used in palliative care; however, the cause of constipation is usually multifactorial.

Constipation is distressing and can cause considerable patient suffering; it needs to be anticipated and appropriately managed. It is important to enquire about defecation because it is easily overlooked. Routine recording of bowel motion frequency, consistency (hard, soft, pasty, loose or watery) and difficulty (straining to pass stools) can help to identify constipation early and prevent it from becoming a significant problem. Patients with minimal oral intake still require preventive measures against constipation.

The consequences of unmanaged constipation include abdominal pain and discomfort, bloating, nausea, vomiting, overflow incontinence, tenesmus, faecal impaction, urinary retention and, occasionally, bowel obstruction, stercoral colitis and colonic perforation. Constipation can also contribute to problems such as delirium, agitated behaviour, depression and anxiety. Unmanaged constipation may interfere with normal absorption of modified-release drugs such as oral modified-release opioids.

Assessment of the cause and type of established constipation in patients with palliative care needs includes recognising change in the patient’s normal bowel routine. The presence of fluid faeces may suggest faecal overflow or faecal impaction. Physical examination (including abdominal and rectal examination) is important to determine the cause and guide appropriate management.

For information on prevention and management, see Prevention of constipation in palliative care and Management of constipation in palliative care.