constipation

Question 1

common in these 3

Answer 1

women
pregnancy
elderly

Question 2

what is it

Answer 2

defecation that is unsatisfactory because of infreq stools, difficult stool passage, seemingly incomplete defection

Question 3

red flags - malignancy? bowel disorder?

Answer 3

• new onset, esp if >50
• anaemia, abdominal pain, weight loss, blood in stool
• review drug if caused by drug

Question 4

advice for all pt with constipation

Answer 4

• increase dietary fibre (whole grains, fruit, veg)
• do this gradually to minimise flatulence and bloating
• effects may be seen in a few days, but may take as long as 4 weeks
• have fruits high in fibre and sorbitol
• adequate fluid intake will help soften stool and make it easier to pass
• this can be difficult in frail and elderly

Question 5

true or false - avoid fruits that are high in sorbitol and fruit juices high in sorbitol if you have constipation

Answer 5

FALSE
e.g. apples, apricots, avocados, cherries, peaches, plums, prunes
These can help prevent and treat constipation

Question 6

laxative abuse can lead to which electrolyte disturbance?

Answer 6

hypokalaemia

Question 7

name 4 bulk forming laxatives

Answer 7

bran
isphagula husk
methyl cellulose
sterculia

Question 8

this bulk forming laxative also acts as a stool softener

Answer 8

methylcellulose

Question 9

onset of action for bulk forming laxatives

Answer 9

up to 72 hours

Question 10

bulk forming laxatives can exacerbate the following symptoms

Answer 10

flatulence, bloating, cramping

(hence why when you counsel pt to increase fibre intake, you advice them to do this gradually)

Question 11

is it important to advice pt to drink enough water when theyre on bulk forming laxatives because…

Answer 11

avoids intestinal obstruction

Question 12

name 5 stimulant laxatives

Answer 12

• bisacodyl
• sodium picosulfate
• senna
• co-danthramer
• co-danthrusate

Question 13

co-danthramer and co-danthrusate are what kind of laxatives?

Answer 13

stimulant

Question 14

how to stimulant laxatives work and what is a common SE

Answer 14

increase intestinal motility, peristalsis
often cause abdominal cramps

Question 15

avoid stimulant laxatives if …

Answer 15

intestinal obstruction

Question 16

use of co-danthamer and co-danthrusate

Answer 16

only used in palliative care/terminally ill because of the potential carcinogenecity and genotoxicity

Question 17

this laxative is believed to act as a stimulant and faecal softener

Answer 17

docusate

Question 18

glycerol suppositories act as ..

Answer 18

lubricant and rectal stimulant due to its mild irritant action

Question 19

how do faecal softeners work

Answer 19

decreasing surface tension and increasing penetration of intestinal fluid into faecal mass

Question 20

these two laxatives have faecal softening properties

Answer 20

docusate (stimulant and softener)
glycerol (lubricant and rectal stimulant)

Question 21

what laxative class would enemas containing arachnis oil fall into and why?

Answer 21

faecal softeners
they lubricate and soften impacted faeces to promote bowel movement

Question 22

Liquid paraffin has been used as a lubricant. However, use with caution because of adverse effects e.g.

Answer 22

anal seepage
risk of granulomatous disease of GIY
lipid pnuemonia on aspiration

Question 23

how do osmotic laxatives work

Answer 23

increase amount of water in large bowel by draining fluid from body into bowel or retaining the fluid they were adminsitered with

Question 24

explain why lactulose is useful in hepatic encephalopathy

Answer 24

• not absorbed from the GIT
• produces osmotic diarrhoea of low faecal pH and discourages proliferation of ammonia producing organisms

Question 25

name 2 osmotic laxatives

Answer 25

macrogol
lactulose

Question 26

ensure macrogol is taken with sufficient fluid to ..

Answer 26

reduce dehydration

Question 27

name two other drugs that are used in constipation

Answer 27

linaclotide
prucalopride

Question 28

MOA lincalotide and when is it used

Answer 28

guanylate cyclase-C receptor agonist
licensed for treatment of moderate to severe IBS associated with constipation
increases intestinal fluid secretion and transit
decreases visceral pain

Question 29

prucalopride MOA and use

Answer 29

selective 5HT3 receptor agonist
has pro kinetic properties (promotes movement in GIT)
licensed for chronic constipation in adults when other laxatives have failed to provide adequate response

Question 30

are bowel cleansing preparations used for constipation

Answer 30

no

Question 31

when are bowel cleansing preparations used

Answer 31

before colonic surgery, colonoscopy or radiological examination to ensure bowel is free of solid contents