Infections and Infestations of the GI Tract

Question 1

What is gastroenteritis?

Answer 1

• Diarrhoea +/- vomiting
• Due to enteric infection
• With virus, bacteria or parasites (schistosomiasis)
• Most commonly viral (50-60%)

Question 2

What is the difference between acute and persistent diarrhoea?

Answer 2

• Acute → > 3 episodes/day for < 14 days
• Persistent → > 14 days

Question 3

What is dysentery?

Answer 3

Infectious gastroenteritis with bloody diarrhoea

Question 4

What is the #1 bacterial cause for gastroenteritis?

Answer 4

Campylobacter

Question 5

What are non-infective causes of diarrhoea?

Answer 5

• IBD
• IBS
• Diverticular disease
• Malabsorption eg. coeliac
• GI lymphoma
• Colorectal cancer

Question 6

What are two important viruses that cause GI infection?

Answer 6

• Norovirus
• Rotavirus

Question 7

What are key features of norovirus?

Answer 7

• Most common cause of GI infection
• Acute onset
• Vomiting / watery diarrhoea / abdo cramps
• Usually self-limiting
• Common in old, young + hosp patients
• Diagnosis → PCR
• Rx → supportive only, isolation

Question 8

What are key features of rotavirus?

Answer 8

• Commonest cause in children (50%)
• Watery diarrhoea / Vomiting / Fever / Abdo pain
• Diagnosis → Stool test (Ag)
• Rx → Supportive

Question 9

What are common bacterial organisms that cause GI infection?

Answer 9

• Campylobacter
• Salmonella
• Shigella
• C. Difficile
• E. Coli

Question 10

What are key features of campylobacter?

Answer 10

• Bloody diarrhoea
• Malaise / Pain / Fever / Headache
• Rx → supportive, abx (clarithromycin, doxcy, macrolide)

Question 11

What are key features of salmonella?

Answer 11

• Bloody diarrhoea
• Cramps / Fever
• Rx → supportive, ciprofloxacin

Question 12

What are key features of shigella?

Answer 12

• Watery and bloody diarrhoea
• Pain / tenesmus / fever
• Diagnosis → stool culture / PCR
• Rx → supportive, nutrition, zinc if <6y, Abx if systemic - ciprofloxacin

Question 13

What are key features of C. Diff?

Answer 13

• Due to overuse of Abx
• Smelly + bloody diarrhoea
• Fever / Colitis
• No vomiting
• Diagnosis → clinical, raised WCC, PCR + culture
• Rx → oral metronidazole / oral vancomycin (severe)
• Isolate for 48H

Question 14

What are key features of E. Coli?

Answer 14

• Most common in type of travellers diarrhoea
• Watery diarrhoea, cramps
• Diagnosis → stool (toxin)
• Rx → supportive

Question 15

What are key features of giardiasis?

Answer 15

• Parasite infection
• Think traveller if not resolving after 3-4 weeks
• Asymptomic diarrhoea (steatorrhoea) / bloating / pain / malabsorption
• Rx → metronidazole / tinidazole / albendazole

Question 16

What is pharmacological treatment for diarrhoea?

Answer 16

• Codeine phosphate 30mg / 8h PO, OR
• Loperamide 2mg PO after each loose stool

Diarrhoea caused by Abx responds to probiotics