Gastroenteritis + infectious colitis

Question 1

Define Gastroenteritis + infectious colitis

Answer 1

Gastroenteritis = acute inflammation of the GI tract

Infectious colitis = inflammation of the colon

Question 2

Aetiology of gastroenteritis

Answer 2

Viral: rotavirus, adenovirus
Bacterial: Camplyobacter jejuni, E. coli (D157), salmonella, shigella, vibrio cholera, listeria
Protozoa: entamoeba histolytica, giardia lamblia
Toxins: S. aureus, C. botulinum, C. perfringens, mushrooms, heavy metals, seafood

Question 3

What organisms are associated with the following: improperly cooked meat, old rice, eggs and poultry, milk and cheese, canned food, Antibiotics, leafy vegetables, person-to-person contact

Answer 3

Improperly cooked meat: S. aureus, Clostridium perfringens

Old rice: B. cereus, S. aureus

Eggs and poultry: salmonella, campylobacter

Milk and cheese: Listeria, Camplyobacter

Canned food: botulism

Antibiotics: C. diff

Leafy vegetables: E. coli (haemorrhage)

Person-to-person contact: shigella

Question 4

Aetiology of Infectious colitis

Answer 4

Direct bacterial or indirect bacterial toxin invasion of the colonic mucosa, leading to toxicity, volume loss, haemorrhage and colonic inflammation

Question 5

What organisms cause dysentry

Answer 5

Camplylobacter/ Clostridium difficile 
Haemorrhagic E. coli 
Entamoeba histolytica 
Shigella 
Salmonella

Question 6

Symptoms of Gastroenteritis + infectious colitis

Answer 6

Nausea and vomiting (sudden onset | Toxins 1-24h after, bacterial/viral/protozoal 12h or later)
Anorexia
Diarrhoea (bloody or watery)
Abdominal pain or discomfort 
Fever and malaise 
Paralysis - botulinum
Fits, renal or liver failure - mushrooms

Question 7

What organisms are the following symptoms associated with:
Water stool with cramps and nausea
Prolonged non-bloody diarrhoea
Profuse rice-water diarrhoea and weight loss (Dehydration)
Severe vomiting 1-6h after eating
Flu-like prodrome followed by cramps pains, fever and diarrhoea
Vomiting within 6 hours due to rice or diarrhoea illness
Gradual onset bloody diarrhoea, abdominal pain and tenderness

Answer 7

Watery stool with cramps and nausea: E. Coli

Prolonged non-bloody diarrhoea: Giardiasis

Profuse rice-water diarrhoea and weight loss (Dehydration): Cholera

Severe vomiting 1-6h after eating: S. aureus

Flu-like prodrome followed by cramps pains, fever and diarrhoea: Campylobacter

Vomiting within 6 hours due to rice or diarrhoea illness: Bacillus cereus

Gradual onset bloody diarrhoea, abdominal pain and tenderness: Amoebiasis

Question 8

Signs of Gastroenteritis + infectious colitis

Answer 8

Diffuse abdominal tenderness
Abdominal distension
Increased bowel

Severe: pyrexia, dehydration, hypotension, peripheral shutdown

Question 9

Investigations for Gastroenteritis + infectious colitis

Answer 9

Stool sample (microscopy, culture): parasites, viral infections (electron), toxins

FBC: WCC raised
ESR/CRP: raised
Blood cultures: +ve for organism

AXR or USS: exclude other cause
Sigmoidoscopy: exclude IBD
Colonoscopy: Colonic inflammation in infectious colitis

Question 10

Management for Gastroenteritis + infectious colitis

Answer 10

1. Bed rest
2. Fluid and electrolyte replacement - oral rehydration (glucose + salt)
3. Severe vomiting -> IV rehydration
4. Antibiotics once infective agent identified

Question 11

What is the specific management for Salmonella, shigella, campylobacter and botulism

Answer 11

Salmonella, shigella, campylobacter -> ciprofloxacin

Botulism: botulinum antitoxin IM and manage in ITU

Question 12

Complications of Gastroenteritis + infectious colitis

Answer 12

Dehydration
Electrolyte imbalance
Pre-renal failure 
Secondary lactose intolerance
Sepsis and shock (salmonella, shigella) 
Haemolytic uraemia syndrome (E. coli)
GBS (Campylobacter)