GI Infections

Question 1

What are clinical features of gastroenteritis?

Answer 1

Abdo pain
Vomiting
Diarrhoea
Fever
Flu like symptoms

Question 2

What are common causes and specific features of gastroenteritis?

Answer 2

E.coli
- most common cause of traveller’s diarrhoea
- loose/watery stools, crampy abdo pain

Giardiasis
- prolonged history of greasy diarrhoea associated with flatulence

Cholera
- uncommon in travellers, associated with watery diarrhoea and severe dehydration

Shigella
- bloody diarrhoea

Amoebiasis
- bloody diarrhoea, associated with liver abscess
- will have derranged LFTs

Staph aureus
- severe vomiting with short incubation period after eating contaminated food

Campylobacter
- history of uncooked poultry e.g. BBQ, flu like prodrome and then crampy abdo pain and loose stools which can be bloody
- if severe/immunocompromised then clarithromycin

Bacillus Cereus
- after eating reheated or takeaway rice- vomiting <6 hours and then diarrhoea after 6 hours

Question 3

What are features of C Difficile?

Answer 3

Gram positive Rod

Often previous history of recent abx esp clindamycin/cephalosporins

Abdo pain/distension/foul smelling watery diarrhoea
Can lead to toxic megacolon

Question 4

What investigations for C diff?

Answer 4

C diff stool toxin

Question 5

What is the management of C diff?

Answer 5

First episode
1) Oral vancomycin 125mg QDS 10 days
2) PO Fidaxomicin 200mg BD 10 days
If life threatening- PO Vanc and IV metronidazole

Further episodes
- within 12 weeks resolution (relapse) PO Fidaxomicin
- >12 weeks (recurrence)- PO fidaxomicin or Vancomycin

Question 6

What are features of small bowel bacterial overgrowth syndrome (SBBOS)?

Answer 6

Diarrhoea
Flatulence
Abdo pain and bloating
Typical risk factors
-scleroderma
- diabetes
- GI Malformations

Question 7

What are investigations and management for SBBOS?

Answer 7

Initial test- H+ breath test
Gold standard: Small bowel aspirate and culture

Management
- Typical rifaximin
- alternatives co-amox/metronidazole

Question 8

What are features of Whipples?

Answer 8

Caused by Tropheryma Whippelei

Risk factors
- HLA B27

Question 9

What are clinical features of Whipples?

Answer 9

Malabsorption- weight loss
Arthralgia
Pleurisy and pericarditis
Lymphadenopathy

Question 10

What are investigations and management of Whipples?

Answer 10

Jejunal biopsy
- deposition of macrophages with period acid-schiff granules and villous atrophy

Management
- prolonged abx
- IV penicillin followed by PO Co-trimxazole for 1 year

Question 11

What are features of tropical sprue?

Answer 11

Infection results in small bowel absorption

Jejunal biopsy- villous atrophy with mononuclear cell infiltrates

Treatment
- 6 months tetracyclines and treat B12/folate deficiency

Question 12

What are features of Giardiasis?

Answer 12

Protozoan Giardia Lamblia

Bloating
Chronic greasy diarrhoea- non bloody
Malabsorptive symptoms

Question 13

What is the investigation of Giardiasis?

Answer 13

String test
-swallow capsule that is tied to cheek- 4-6 hours can be pulled up and sent for MCS

Management
- Metronidazole

Question 14

What are features of H.Pylori infection?

Answer 14

Gram -ve bacteria that grows in stomach mucosa
- produced ammonia, proteases and cytotoxins that causes ulcers

Can lead to
- peptic ulcer disease
- gastric cancer
- Gastric B cell MALT lymphoma

Question 15

What is the investigation of H.pylori?

Answer 15

Urea breath test
- must avoid abx for 4 weeks and PPI for 2 weeks
- drink 13C urea and then measure breath

CLO test- biopsy sample mixed with urea

Gold standard- gastric biopsy and culture