Diarrhoea

Question 1

What is the normal fluid balance of the adult GIT in 24 hours?

Answer 1

10L in
100mL excreted
9.9L absorbed (can absorb 4-5L more if needed)

Question 2

What is the difference in the clinical presentation of diarrhoea originating in the small vs. large intestine?

Answer 2

Small: too much fluid enters colon, results in increased volumes of watery diarrhoea
Large: damaged colon can’t store contents, results in frequent passing of low volume stools

Question 3

What are the most common agents of infective diarrhoea in developing vs. developed countries?

Answer 3

Bacterial in developing countries

Viral in developed countries

Question 4

What are the 3 aetiological agents of non-specific gastro?

Answer 4

Viruses
Bacteria
Protozoa

Question 5

List 3 infective agents which can cause dysentry

Answer 5

Shigella
EIEC
Protozoa

Question 6

List 8 infective agents which can cause foodborne diarrhoea

Answer 6

Staph
Salmonella
Clostridium (perfringens most commonly)
Bacillus
Vibrio
Listeria
Viruses (e.g. norovirus on cruise ships)
Ciguatoxin

Question 7

List 3 infective agents which can cause travellers’ diarrhoea

Answer 7

ETEC (and other bacteria)
Viruses
Protozoa

Question 8

What is the infective agent responsible for antibiotic-associated pseudomembranous colitis?

Answer 8

Clostridium difficile

Question 9

What is the infective agent responsible for haemorrhagic colitis?

Answer 9

EHEC

Question 10

List 2 infective agents which can cause cholera-like diarrhoea

Answer 10

Vibrio cholerae

ETEC

Question 11

List 2 infective agents which can cause enteric fever

Answer 11

Salmonella typhi

Salmonella paratyphi

Question 12

What is dysentry?

Answer 12

Diarrhoea characterised by the presence of blood, pus and mucus in the faeces

Question 13

Are all causes of dysentry infectious?

Answer 13

No: can be caused by acute colitis (non-infectious) and cancer

Question 14

EIEC

Answer 14

Entero-invasive E. coli (Shigella-like)

Question 15

EHEC

Answer 15

Entero-haemorrhagic E. coli

Question 16

ETEC

Answer 16

Entero-toxigenic E. coli

Question 17

EPEC

Answer 17

Entero-pathogenic E. coli

Question 18

EAEC

Answer 18

Entero-aggregative E. coli

Question 19

What is the most common cause of foodborne diarrhoea?

Answer 19

Ingestion of Staph toxin

Question 20

How are bacteria classified according to the degree of mucosal invasion, from least to most invasion?

Answer 20

Adhesive enterotoxigenic
Adhesive with brush border damage
Invasion restricted to mucosa
Invasion of submucosa
Systemic invasion

Question 21

Give 2 examples of diarrhoeal agents which are adhesive enterotoxigenic

Answer 21

ETEC

Cholera

Question 22

Give an example of a diarrhoeal agent which are adhesive and cause brush border damage

Answer 22

EPEC

Question 23

Give an example of a diarrhoeal agent which invades but is restricted to the mucosa

Answer 23

Shigella

Question 24

Give 2 examples of diarrhoeal agents which invade the submucosa

Answer 24

Salmonella

Campylobacter

Question 25

Give an example of a diarrhoeal agent which invades systemically

Answer 25

Salmonella

Question 26

Which strains of E. coli produce Shiga toxin?

Answer 26

EHEC | Shiga toxin-producing EAEC (acquired via bacteriophage)

Question 27

What are the 3 classes of anti-diarrhoeals?

Answer 27

Opioids Musculotropic antispasmodic Muscarinic receptor antagonists

Question 28

Loperamide

Answer 28

Opioid

Question 29

Mebeverine

Answer 29

Musculotropic antispasmodic

Question 30

Hyoscine butylbromide

Answer 30

Muscarinic receptor antagonist (also used to treat PUD)