Drugs altering GI motility

Question 1

Lower GI motility symptoms

Answer 1

diarrhoea
constipation

Question 2

How should you describe poo? What is classed as diarrhoea consistency-wise?

Answer 2

Bristol stool chart
Type 6/7 = diarrhoea

Question 3

Define diarrhoea

Answer 3

passage of loose or watery stools, typically at least 3 times in 24 hours
reduced consistency
increased frequency

Question 4

Define dysentery

Answer 4

symptom, not a disease
diarrhoea with visible blood or mucus (commonly associated with fever and abdominal pain)

Question 5

Acute diarrhoea causes

Answer 5

infections - viral, bacterial, protozoal (eg. giardia)
drugs

Question 6

Types of chronic diarrhoea

Answer 6

osmotic diarrhoea
secretory diarrhoea

Question 7

Describe osmotic diarrhoea

Answer 7

water is drawn in or retained in the bowel due to the presence of solutes within the lumen, typically due to:
- ingestion of poorly absorbed solute
- malabsorption

fasting reduces the diarrhoea

Question 8

Osmotic diarrhoea causes

Answer 8

carbohydrate malabsorption eg. lactose intolerance
magnesium-induces
osmotic laxatives (eg. lactulose)
small intestinal mucosal disease
reduced absorptive area
bile acid malabsorption
pancreatic exocrine insufficiency

Question 9

Secretory diarrhoea causes

Answer 9

bacterial endotoxins (eg. E coli, cholera, C diff)
stimulant laxatives (eg. senna)
hormones (eg. hyperthyroidism)
bile acid malabsorption
mucosal inflammation (UC, Crohn’s)
rectal villous adenoma

Question 10

Diarrhoea treatment

Answer 10

treat underlying disorder
stop causative medications
opiates
anti-secretory drugs eg. ocreotide (somatostatin analogue)

Question 11

What is constipation?

Answer 11

slow colonic transit, impaired rectal emptying, or both

Question 12

Constipation causes

Answer 12

endocrine - hypothyroidism
metabolic - hypercalcaemia, hypokalaemia, hypomagnesaemia
neurological - MS, hemiplegia
neuromuscular - MND, MG
psychological
physiological - not drinking enough
mechanical - obstruction (malignancy)

Question 13

Constipation treatment

Answer 13

identify anatomical abnormalities
identify biochemical causes
stop constipating drugs
exercise
increase fluid intake
increase dietary fibre
laxatives

Question 14

Side effects of increasing dietary fibre

Answer 14

bloating
flatulence

Question 15

How do bulk-forming laxatives work? Name some examples

Answer 15

improves bowel frequency rather than consistenca
ispaghula, sterculis

Question 16

How do stimulant laxatives work? Name some examples

Answer 16

increases motility, frequency, improves consistency
minimise usage to decrease risk of atonic colon
bisacodyl
senna
sodium picosulphate

Question 17

What is melanosis coli?

Answer 17

pigmentation of colonic mucosa
can be caused by overuse of stimulant laxatives
occurs alongside atonic colon

Question 18

Name some stool softeners

Answer 18

sodium docusate
liquid paraffin
arachis oil enema (contains peanuts)

Question 19

Name 2 osmotic laxatives

Answer 19

lactulose
magnesium salts

Question 20

How does lactulose work?

Answer 20

syrup derived from lactose
decreases colonic pH by generation of fatty acids and fermentation products

Question 21

Lactulose side effects

Answer 21

bloating
flatulence

Question 22

Magnesium salts side effects

Answer 22

hypermagnesaemia

Question 23

What drug can be used to treat opioid induced constipation if other laxatives haven’t worked?

Answer 23

Naloxegol

Question 24

Name some newer anti-constipation drugs

Answer 24

prucalopride
lubiprostone
linaclotide