Infections of the GI tract and hepatobiliary system

Question 1

How do you define diarrhoea?

Acute vs persistent vs chronic definitions?

Answer 1

Passage of loose or watery stools at least 3x a day in 24 hours
Acute <14 days
Persistent 14-20d
Chronic >30days

Question 2

What is the combination of bloody diarrhoea, fever and abdominal pain commonly referred to as?

Answer 2

Dysentry

Question 3

Name some non-infective causes of diarrhoea

Answer 3

Cancer
chemicals (poisoning, sweeteners, medication side effects)
IBD
IBS
Endocrine causes (thyroid dysfunction)
Radiation
Coeliac
etc.

Question 4

What type of organism are the most common cause of watery diarrhoea?
Name 2

Answer 4

Viruses
Rotavirus
Norovirus

Question 5

Name some bacterial & parasitic causes of watery diarrhoea

Answer 5

• Vibrio cholerae
• E coli
• clostridium perfringens
• bacillus cereus
• staph aureus

Parasitic

• Giardia
• Cryptosporidium

Question 6

Name some bacterial and parasitic causes of bloody diarrhoea

Answer 6

Bac:
shigella
campylobacter jejuni
salmonella
e coli
yersinia spp
c diff

Parasitic
- entamoeba histolytica

Question 7

What virus is the most common cause of diarrhoea in children <2?

Answer 7

Rotavirus

Question 8

How is norovirus obtained? Where do we commonly see outbreaks?

Answer 8

Caused by ingesting contaminated shellfish and seafood.

Outbreaks in hospitals, restaurants and ships

Question 9

How is cholera acquired?
How does cholera cause diarrhoea?
What type of diarrhoea can it cause?

Answer 9

Acquired from contaminated water
Cholera toxin is produced which stimulates the secretion of water and electrolytes from the epithelial cells in the lumen
Can cause rice water diarrhoea with water loss exceeding 1L per hour leading to rapid dehydration.

Question 10

What is the most common cause of travellers diarrhoea? How is it acquired?

Answer 10

Enterotoxigenic E coli (ETEC)

- acquired by ingesting faecally contaminated food or water

Question 11

Name some causative agents of food poisoning?

Answer 11

Clostridium perfringens
Bacillus cereus - reheating rice inadequately
Staphylococcus aureus - certain strains

Question 12

What is a common organism which causes hospital acquired diarrhoea?

Answer 12

clostridium difficile

• spore forming toxin. producing gram positive anaerobic bacteria
• occurs when the normal flora is changed - PPIs, antibiotics (clindamycin, coamoxiclav, ceftriaxone)

Question 13

How do we treat c diff?

Answer 13

Stop offensive antibiotic
Soap and water hand washing more effective than alcohol gels
Metronidazole or oral vancomycin

Question 14

Name 2 parasitic organisms which can cause diarrhoea

Answer 14

Giardia duodenalis:
- common in areas with poor sanitation and limited water treatment facilities
Cryptosporidium:
- contaminated drinking or swimming water
- self limiting in healthy individuals but can cause chronic illness in immunosuppressed patients

Question 15

What are the indications for testing in diarrhoea?

Answer 15

If there is severe illness (hypovolemia, severe abdo pain or requiring hospitalisation)
If there is bloody diarrhoea and mucus - stool antigen test
In high risk patients (age >70, immunocompromised patients, IBD, pregnant women)
Symptoms persistent for more than 1 week
Public health concern (diarrhoea illness in food handlers or those working in day care centres)

Question 16

Key management principles for diarrhoea?

Answer 16

• Fluid replenishment & electrolyte replacement
• Good sanitation
• Notify PHE of cases of food poisoning, bloody diarrhoea, HUS
• Certain cases to give antibiotics - c diff, cholera, giardia, salmonella

Question 17

What is acute cholecystitis? 
Symptoms?
Eating what exacerbates the symptoms?
How is it diagnosed?
Treatment?
Surgery?

Answer 17

• Gall bladder inflammation, cystic duct obstruction by gall stones
• RUQ or epigastric pain, fever and leukocytosis
• Exacerbated by fatty food consumption
• Diagnosed by USS
• Treatment: IV fluids, analgesia and antibiotics
• Surgery: cholecystectomy definitive treatment

Question 18

What is ascending/acute cholangitis?
Symptoms?
Diagnosis?
Management?

Answer 18

• Obstruction of the common bile duct by stone or stricture
• Fever, abdominal pain & jaundice (charcot’s triad)
• ERCP: diagnostic and therapeutic
• Management: prompt admission and IV antibiotics, ERCP, cholecytectomy
• High mortality rate!

Question 19

How do we diagnose H. pylori?

What is the treatment for H. pylori?

Answer 19

Stool antigen test

Treatment: triple therapy with PPI’s, amoxicillin and clarithromycin

Question 20

What is peritonitis?

Answer 20

Inflammation of the visceral and parietal peritoneum secondary to an infectious or inflammatory process

Question 21

What are some primary causes of peritonitis?

What is a secondary cause of peritonitis?

Answer 21

• Spontaneous without cause of contamination
• Usually due to underlying cirrhosis and ascites
• TB
• Pelvic inflammatory disease

Secondary:
- Perforation and spillage of the GIT (trauma or appendicitis)

Question 22

What organism causes enteric fever? Where is enteric fever endemic? Does it affect young children or adults more commonly?

Answer 22

Salmonella Typhi and Salmonella Paratyphi
Endemic in Central Asia, Southeast Asia and Southern Africa
- Affects young children more commonly than elderly

Question 23

Presentation of enteric fever?
Diagnosis?
Treatment?

Answer 23

• Generalised abdominal pain, high range fever and chills
• Severe headache and myalgia
• ‘Relative bradycardia’
• Rose spots - spots on torso
• Constipation or green diarrhoea after about 2 weeks

Diagnosis
- Blood cultures or bone marrow aspiration

Treatment
- Antibiotics - azithromycin, ciprofloxacin, cephalosporins.