Diarrhoea

Question 1

Define Diarrhoea

Answer 1

> 200g stool/24hrs
OR
3+ stools/day + loose

acute <2 weeks
chronic >4 weeks

Question 2

How much fluid is secreted in the GI tract? How much is absorbed?

Answer 2

9L in (saliva, intestine, bile, pancreas, gastric, diet)
0.1L out (small bowel, large bowel)

Question 3

What is ORS made up of?

Answer 3

1L water
3.5g NaCl
2.5g NaCO3
1.5g KCl2
20g glucose

Question 4

What are the most common causes of acute diarrhoea?

Answer 4

virus - rota/adeno/noravirus

bacteria - Campylobacter jejuni, then E.Coli, salmonella, shigella

parasitic - Giardia lamblia is most common, Entamoeba histolytica, Cryptosporidium spp

non-infectious - food intolerances, IBD, drugs, alcohol

Question 5

How can you differentiate between pancreatic and SB steatorrhoea?

Answer 5

Pancreatic: 
normal RBC folate
faecal fat >20g/24hrs
faecal elastase
ERCP + normal imaging

Small Bowel:
low RBC folate
Anti-TTG antibodies
Bx
CT/MRE

Question 6

List some drugs which can cause diarrhoea

Answer 6

alcohol
abx
anti-depressants
NSAIDs
anti-hypertensives
statins
GI drugs
biguanides

Question 7

What is Osmotic Diarrhoea?

Answer 7

= a high concentration of solute in bowel
drags water back into the lumen
eg high salt/sugar, malabsorption

Question 8

What is Secretory Diarrhoea?

Answer 8

= an increase in the active secretion or there is an inhibition of absorption
little to no structural damage
eg enterotoxins from E.Coli

Question 9

What are the types of diarrhoea?

Answer 9

Osmotic
Secretory
Motility
Inflammatory
Exudative = blood in the stool

Question 10

What is FODMAP?

Answer 10

fermentable oligosaccharides dissacharides monosaccharides and polyols

Question 11

What is Clostridium Difficile?

Answer 11

anaerobic gram -ve spore-forming bacteria
faecal-oral route
toxins A & B
most common in elderly, IBD
--> life-threatening

Question 12

What defines the severity of C.Difficile and how is it managed?

Answer 12

mild - 3 stools/24hrs, normal WCC - PO Metronidazole

moderate - 3-5 stools, <20 WCC - PO M

severe - >20 WCC, >38.5 temp, raised CRP, abdo pain - PO vancomycin

complicated - hypotensive, partial ileus, severe disease on CT - PO vancomycin + IV metronidazole

life-threatening - complete ileus or TMC - PO vancomycin + IV metronidazole + faecal transplant (potential colectomy)