constipation

Question 1

constipation + what are red flags

Answer 1

constipation - infrequent, difficult stools - most common in women, pregnant, elderly

red flags:
blood in stool
anaemia
abdominal pain
weight loss
new onset constipation over 50 years

Question 2

first line treatment

Answer 2

non drug:
increase dietary fibre
increase fluid
increase exercise

review meds that might be causing it

Question 3

diff laxative agents and moa

Answer 3

bulk forming (methylcellulose, isphagula hulk) - increase faecal mass, stimulates peristalsis
- take 2/3 days to work
- must be taken with enough water to prevent intestinal blockage

stimulant (senna, bisacodyl, docusate)
- stimulate colonic nerves - peristalsis
- take 6-12 hrs to work
- avoid in intestinal obstruction
- co-danthramer and co-danthrusate used only in terminal illnesses due to carcinogenicity (red urine)

faecal softeners (docusate, bisacodyl)
- increases water penetration to stool
- quickest acting (docusate enema takes 5-20 mins)
- liquid paraffin avoided due to anal seepage

osmotic (lactulose, macrogol)
- brings water into the large bowel - peristalsis
- take 2/3 days to work
- faecal softening properties

prokinetic agents (prucalopride, lubiprostone) - enhance gut motility via serotonin receptor activation or chloride channel stimulation

Question 4

drug treatment for short duration

Answer 4

1 - bulk forming + good hydration
2 - osmotic

Question 5

drug treatment for chronic constipation (> 6 months)

Answer 5

1 - bulk forming + good hydration
2 - is stool remains hard - osmotic
3- still no change after 6 months - prucalopride

Question 6

drug treatment for faecal impaction

Answer 6

hard stool - macrogol + stimulant once softened

soft stool - stimulant

Question 7

drug treatment for opioid-induced

Answer 7

1 - osmotic + stimulant

2 - naloxegol if no response to 1st line

AVOID BULK FORMING - can cause obstruction/faecal impaction

Question 8

drug treatment for pregnancy/breastfeeding

Answer 8

1 - dietary and lifestyle - bran and wheat fibre

2 - bulk forming, lactulose

3 - bisacodyl or senna (dont use senna near term)

Question 9

drug treatment for children

Answer 9

1 - dietary advice + macrogol (if no faecal impaction), then stimulant

2 - if stool is hard - lactulose or docusate