Diarrhoea

Question 1

What’s the most common cause of Gastro-enteritis

Answer 1

Viruses, with Campylobacter being the commonest bacterial cause

Question 2

Commonest food poisoning pathogen?

Answer 2

Campylobacter

Question 3

What pathogen causes the most Hospital admissions

Answer 3

Salmonella

Question 4

3 catagories of Diarrhoeal illnes

Answer 4

Non-inflammatory/secretory

Inflammatory

Mixed Picture

Question 5

Clinical features of non-inflammatory diarrhoea + treatment + responsible organisms

Answer 5

Frequent watery stools, with little abdo pain

Rehydration mainstay of therapy

E. coli and Cholera

Question 6

What is increased in Cholera

Answer 6

cAMP levels and Cl secretion

Question 7

Clinical features of inflammatory diarrhoea + treatment + responsible organisms

Answer 7

Pain + fever, inflammatory toxin damage + muscoal destruction

Antimicrobials MAY be appropriate but rehydration is often sufficient.

Bacterial infection / amoebic dysentery

Question 8

What organism is likely responsible for mixed diarrhoeal symptoms

Answer 8

C. difficile

Question 9

How to assess a patient with diarrhoea

Answer 9

Symptoms + duration (>2wk hx UNLIKELY to be infective gastro-enteritis

Risk of food poisoning (Diet, contact, travel hx)

Assess Hydration (postural BP, skin turgor, pulse)

Features of inflammation (Fever, raised WCC, ?CRP?)

Question 10

How severe can fluid loss be and what Hypos are asscoiate with it

Answer 10

1-7L/day

Hyponatraemia, due to sodium loss with fluid replacement with hypotonic solutions

Hypokalaemia, due to K loss in stool

Question 11

Investigations to be carried out

Answer 11

Stool + blood culture
Renal function
FBC (neutrophilia, haemolysis)
Abdo x-ray (if abdo is distended + [?tender?])

Question 12

Diff diagnosis for diarrhoea

Answer 12

IBD
Spurious diarrhoea (secondary to constipation)
Carcinoma

Question 13

What may cause diarrhoea that has no relation to the GI tract (would also be part of your diff diagnosis)

Answer 13

Diarrhoea + fever can occur with SEPSIS OUTSIDE THE GUT

• Lack of abdo pain/tenderness goes against gastroenteritis
• no blood/mucus in stools

Question 14

Treatment for Gastroenteritis

Answer 14

IV (saline) or Oral (salt/sugar solution) Rehydration

Question 15

Clinicial features of Campylobacter Gastroenteritis

Answer 15

Up to 7 day incubation (dietary hx may be unreliable)
Abdo pain can be severe
Can cause Guillain-Barre syndrome and reactive athritis post infection

Question 16

Clinical features of Salmonella Gastroenteritis

Answer 16

Symptoms usually onset <48hrs post exposure
Diarrhoea usually lasts <10 days
Post-infective irritable bowel is common

Prolonged carriage may be asscociated with gallstones

Question 17

Clinical features of E. coli 0157 infection

Answer 17

Frequent BLOODY stools
E. coli stays in gut but toxin gets into the blood
Toxin can cause Haemolytic-uraemic Syndrome (HUS)

Question 18

Symptoms of HUS

Answer 18

Haemolytic anaemia
Renal Failure
Thrombocytopenia

Question 19

Treatment for HUS

Answer 19

Supportive

ANTIBIOTICS NOT INDICATED

Question 20

When are antibiotics indicated in Gastroenteritis

Answer 20

Immunocompromised 
Severe sepsis or invasive infection 
Valvular heart disease
Diabetes 
Chronic illness

Question 21

When are antibiotics NOT indicated in Gastroenteritis

Answer 21

Healthy patient with NON-invasive infection

Question 22

Clinical features of C. difficile diarrhoea

Answer 22

Usually hx of atibiotic treatment with 4C’s (Clindamycin, Cephalosporins, Co-amoxiclav and Ciprofloxacin)

Severity ranges from mild diarrhoea to severe colitis

Question 23

Treatments for C. diff

Answer 23

STOP PRECIPATING ANTIBIOTIC (if possible)
Oral Metronidazole (if no severity markers)
Oral Vancomycin (if 2 or more severity markers)

Fidaxomicin (new + expensive)
Stool transplant
Surgery

Question 24

Causes of Viral diarrhoea

Answer 24

Adenovirus

Rotavirus in children under 5yrs

Question 25

When is viral diarrhoea more common

Answer 25

Winter

Question 26

How is viral diarrhoea diagnosed

Answer 26

Antigen detection

Question 27

Common cause of viral diarrhoea outbreaks

Answer 27

Norovirus (very infectious)

common in hospitals, small communities and cruise ships.

Question 28

How is Norovirus diagnosed

Answer 28

PCR