Constipation

Question 1

What is the aetiology of constipation?

Answer 1

Causes of constipation include:

    organic obstruction
    painful anal conditions (anal fissure)
    adynamic bowel
    drugs
    habit and diet
    metabolic imbalance

Question 2

What is the pathophysiology of constipation?

Answer 2

• Multifactorial
• Commonly low fibre diet + not drinking enough
• • low activity
• obesity
• ignoring the urge to defecate
• LT use of laxatives = atonic bowel
• Codeine/opiates reduce gut motility
• Iron solidifies stools
• Endocrine e.g. hypOthyrodism and hypercalcaemia

Question 3

What are the clinical features of constipation?

Answer 3

• infrequent, incomplete evacuation of stools
• anorexia and vague abdominal discomfort
• diarrhoea - constipation may cause overflow, especially in the elderly, when faecal fluid intermittently escapes past an impacted faecal mass
• acute abdominal pain - usually in children - or features of intestinal obstruction - usually in the elderly

Question 4

How is constipation investigated?

Answer 4

Children: history and examination

Elderly: sigmoidoscopy and barium enema to rule of carcinoma and diverticular disease + review drug history for aetiological agent

Question 5

How is constipation managed?

Answer 5

• Drugs NOT first line
• Find underlying cause and treat
• Mobilise patient and encourage fibre rich diet and adequate fluid intake
• Only consider drugs if the above measures have failed
• Short course of laxatives may relieve symptoms
• Prolonged laxatives not generally indicated
• Only indicated in faecal impaction where patient may be immobile due to age/illness or receiving opioids due to palliative care