GI: Constipation

Question 1

What are the bulk-forming laxatives? (4)

Answer 1

Bran
Ispaghula
Methylcellulose (also faecal softener)
Sterculia

Question 2

What are the stimulant laxatives? (4)

Answer 2

1. Bisacodyl
2. Sodium picosulfate
3. Senna
4. Co-danthramer/co-danthrusate

Glycerol acts as a lubricant and as a rectal stimulant by virtue of the mildly irritant action of glycerol.

Docusate sodium is believed to act as both a stimulant laxative and as a faecal softener.

Question 3

How do stimulant laxatives work?

Answer 3

Increase intestinal motility and often cause abdominal cramp.

Question 4

What are the faecal softener laxatives? (4)

Answer 4

1. Docusate sodium
2. glycerol supp
3. Arachis oil
4. Liquid paraffin

Question 5

What are the osmotic laxatives? (2)

Answer 5

1. Lactulose - decreases proliferation of ammonia-producing organisms so useful in treatment of hepatic encephalopathy.
2. Macrogols.

Question 6

What is linaclotide?

Answer 6

Linaclotide is a guanylate cyclase-C receptor agonist that is licensed for the treatment of moderate to severe IBS associated with constipation.

It increases intestinal fluid secretion and transit, and decreases visceral pain.

Question 7

What is lubiprostone?

Answer 7

Lubiprostone is a chloride-channel activator that is licensed for the treatment of chronic idiopathic constipation in adults whose condition has not responded adequately to lifestyle changes.

Question 8

What is prucalopride?

Answer 8

Prucalopride is a selective serotonin 5HT4-receptor agonist with prokinetic properties.

It is licensed for the treatment of chronic constipation in adults, when other laxatives have failed to provide an adequate response.

Question 9

What laxatives should be used/avoided in patients with opioid-induced constipation?

Answer 9

In patients with opioid-induced constipation, an osmotic laxative (or docusate sodium to soften the stools) and a stimulant laxative is recommended. Bulk-forming laxatives should be avoided.

Question 10

What is the first choice laxative during pregnancy?

Answer 10

A bulk-forming one if fibre supplements fail.

Question 11

What is the second choice laxative in pregnancy?

Answer 11

An osmotic laxative, such as lactulose, can also be used. Bisacodyl or senna may be suitable if a stimulant effect is necessary but use of senna should be avoided near term or if there is a history of unstable pregnancy. Stimulant laxatives are more effective than bulk-forming laxatives but are more likely to cause side-effects (diarrhoea and abdominal discomfort), reducing their acceptability to patients. Docusate sodium and glycerol suppositories can also be used.