Laxatives - Stimulant

Question 1

There are 4 basic layers of the GIT. Organise them with the closest layer to the lumen 1st:

1 - mucosa
2 - serosa
3 - muscularis externa also known as muscularis propria
4 - submucoas

Answer 1

1 - mucosa
4 - submucoas
3 - muscularis externa also known as muscularis propria
2 - serosa

Question 2

In the 3rd layer of the GIT is the muscularis externa, contains smooth muscle. There are 2 layers of smooth muscle, an inner circular layer and an outer longitudinal layer. Together these perform peristalsis. Which of these layers is responsible for stopping food move backwards, and which is responsible for moving food forward?

Answer 2

• stopping food moving backwards = INNER CIRCULAR LAYER
• moving food forward = OUTER LONGITUDINAL LAYER

Question 3

The 3rd layer of the GIT is the muscularis externa, containing an inner circular and an outer longitudinal layer os smooth muscle. This is separated by what?

1 - submucosal nerve plexus
2 - lamina propria
3 - myenteric nerve plexus
4 - muscularis mucosa

Answer 3

3 - myenteric nerve plexus

Question 4

Which of the following is NOT contained within the dense submucosal layer?

1 - arteries
2 - veins
3 - submucosal nerve plexus
4 - lamina propria

Answer 4

4 - lamina propria

Question 5

Which 2 of the following are the functions of the submucosa plexus contained within the submucosal layer of the GIT?

1 - peristalsis of the GIT
2 - control of blood vessels
3 - secretion of mucus
4 - GIT secretions

Answer 5

2 - control of blood vessels
4 - GIT secretions

Question 6

The mucosa contains 3 separate layers. Which of the following is NOT a layer of the mucosa?

1 - muscularis mucosa
2 - submucosal nerve plexus
3 - lamina propria
4 - epithelial layers

Answer 6

2 - submucosal nerve plexus

• muscularis mucosa = break up food
• lamina propria = blood and lymph vessels
• epithelial layers = absorbs and secretes mucus and GIT secretions

Question 7

According to NICE, diarrhoea is the abnormal passage of loose or liquid stools. Which 2 of the following are needed in a patient to be diagnosed with acute diarrhoea?

1 - >3 times/day daily and/or a volume of stool >200g/day
2 - >10 times/day and/or stool volume >500g/day
3 - <14 days in duration
4 - >14 days in duration

Answer 7

1 - >3 times/day daily and/or a volume of stool >200g/day

3 - <14 days in duration

• chronic diarrhoea is >4 weeks

Question 8

Which of the following are included in the definition of constipation?

1 - <3 bowel movements/wk
2 - excessive straining
3 - abdominal pain or bloating
4 - all of the above

Answer 8

4 - all of the above

Question 9

Which of the following are included in the definition of chronic constipation?

1 - <3 bowel movements/wk
2 - excessive straining
3 - abdominal pain or bloating
4 - symptoms present in 12 weeks of the last 6 months
5 - all of the above

Answer 9

5 - all of the above

Question 10

Which 2 of the following are the stimulant laxatives that we need to know?

1 - ispaghula husk
2 - senna
3 - glycerol suppositories
4 - docusate sodium

Answer 10

2 - senna
3 - glycerol suppositories

Question 11

Senna and glycerol suppositories are the 2 core stimulant laxatives that we need to know. Which of the following are how stimulants help with bowel movements?

1 - irritate bowels inducing mild inflammation
2 - encourage fluid and electrolyte secretion into lumen
3 - stimulate enteric nervous system
4 - all of the above

Answer 11

4 - all of the above

• senna is metabolised to sennosides, this is the irritant

Question 12

Senna and glycerol suppositories are the 2 core stimulant laxatives that we need to know. Which of the following are they indicated in the use of?

1 - diverticulosis
2 - bowel obstruction
3 - constipation
4 - bowel preparation prior to procedure

Answer 12

3 - constipation

Question 13

How are stimulant laxatives typically administered?

1 - orally
2 - IV
3 - suppository
4 - IM

Answer 13

1 - orally
- effective in 6 hours

3 - suppository
- effective in 15-30 minutes

• need to ensure patient has adequate fluid levels prior to use

Question 14

Which of the following are common adverse events of stimulant laxatives?

1 - abdominal cramps
2 - diarrhoea
3 - nausea
4 - abnormal U&Es
5 - all of the above

Answer 14

5 - all of the above

• Senna can also cause melanosis coli

Question 15

Which of the following are stimulant laxatives contra-indicated in?

1 - GIT atony
2 - intestinal obstruction
3 - undiagnosed abdominal pain
4 - all of the above

Answer 15

4 - all of the above

Question 16

Which drug class are laxatives generally prescribed alongside?

1 - NSAIDs
2 - Ca2+ channel blockers
3 - opioids
4 - benzodiazepines

Answer 16

3 - opioids