Constipation

Question 1

Constipation History

Answer 1

• Ask about frequency, consistency and nature of the stool
• Red flags:
• Unexplained change in bowel habit, palpable mass, persistent rectal bleed without anal symptoms, narrowing of stool calibre, FHx, unexplained weight loss, iron deficiency anaemia, fever or nocturnal symptoms, severe, persistent constipation
• A lot of causes

Question 2

Constipation Ix

Answer 2

Indications for investigation

• Age >40
• Recent change in bowel habit
• Associated symptoms (weight loss, rectal bleeding, mucous, tenesmus)

Possible investigations

• Bloods (FBC, U&Es, calcium, TFTs)
• Sigmoidoscopy if signs of CA

Question 3

Constipation Management

Answer 3

Bulking agents (isphasgula, bran powder, methycellulose)

• Increase faecal mass
• Take with plenty of water
• CI: difficulty swallowing, obstruction, colonic atony, impaction

Stool softeners (arachis oil enema)
-Side effects: anal seepage, lipoid pneumonia, malabsorption of fat-soluble vitamins

Stimulant (bisacodyl, docusate sodium, Senna)

• Increase intestinal motility, not for obstruction
• CI: obstruction
• Avoid prolonged use

Osmotic Agents

• Retain fluid in the bowel
• Lactulose creates osmotic diarrhoea with low pH that discourages ammonia-producing organisms
• Magnesium salts when rapid bowel evacuation is required
• Macrogols can be used in long term management

If two different laxatives have failed for 6 months try prucalopride (5HT4 agonist with prokinetic properties)