Diarrhoea

Question 1

What is diarrhoea?

Answer 1

Decreased stool consistency

Question 2

What are the 3 categories of diarrhoea?

Answer 2

Osmotic (watery) diarrhoea
Steatorrhoea (fatty) diarrhoea
Inflammatory discharge (blood + mucus) diarrhoea

Question 3

What causes osmotic diarrhoea?

Answer 3

Infection
Laxative induced
Functional: IBS

Question 4

What causes Steatorrhoea?

Answer 4

Biliary problems, lack of bile
Pancreatic problems
Malabsorption: IBD
Coeliac
Giardiasis

Question 5

What causes inflammatory discharge diarrhoea?

Answer 5

IBD: Crohn’s, UC
Colorectal cancer
Infection

Question 6

How can you distinguish between:

• osmotic diarrhoea
• Steatorrhoea
• inflammatory discharge diarrhoea?

Answer 6

Osmotic: just watery faeces really

Steatorrhoea: flatulence, offensive smell, floating of stool (hard to flush)

Inflammatory discharge diarrhoea: blood and mucus

Question 7

What do you need to ask when taking a history of diarrhoea?

Answer 7

Occupation: are they likely to infect someone else?

Acute or chronic:

• acute indicates gastroenteritis/infection
• chronic indicates IBD, cancer

Any change in diet? (Coeliac, lactose intolerance)

Anyone else affected? (if yes likely to be infectious)

Any fever? Pain?

Does it alternate between diarrhoea + constipation? (IBS)

Any weight loss? (cancer)

Nocturnal diarrhoea? (IBD)

Any blood or mucus? (IBD, cancer, infection)

Any pus? (IBD, diverticulitis, abscess)

Explosive? (infectious)

Are there any signs of HIV?

Question 8

Patient has peri-umbilical pain that is not relieved by defaecation. Small or large bowel problem?

Answer 8

Small

Question 9

Patient has pelvic pain relieved by defaecation. Small or large bowel problem?

Answer 9

Large

Question 10

Differential diagnosis of diarrhoea?

Answer 10

Gastroenteritis
Parasites
IBS
Colorectal cancer
IBD
Coeliac disease
Drugs, especially antibiotics

Question 11

What is gastroenteritis?

Answer 11

Inflammation of the stomach or gut usually caused by an infection

Question 12

Investigations of diarrhoea?

Answer 12

Look for signs of dehydration

Rectal exam: check for masses or impacted faeces

Bloods:

• FBC check for anaemia, could indicate cancer or coeliac
• ESR/CRP raised in infection, IBD + cancer
• U&E low potassium caused by severe V+D
• Cultures could show infection
• Serology for coeliac

Stool:

• Culture for bacteria, parasites etc.
• Faecal fat + blood

Endoscopy

Question 13

Management of diarrhoea?

Answer 13

Treat the causes!

If infectious:

• antibiotics
• notify if notifiable disease
• ensure they stay away from work if food handlers
• close wards if inpatient

Rehydrate with fluids orally before IV

Medication to reduce stool frequency and make stools firmer: loperamide

Question 14

Which pathogens are usually responsible for diarrhoea?

Answer 14

Viruses
- norovirus

Bacteria:

• C. difficile
• Staph. aureus
• Salmonella
• Shigella
• E. coli

Question 15

Which bacteria causes bloody diarrhoea?

Answer 15

Shigella species

Enterohaemorrhagic type E. coli

Question 16

Explain the link between antibiotics and C. diff?

Answer 16

Antibiotics prescribed for any reason can wipe out the natural flora in the gut

The natural flora usually protect the gut against other infections

If wiped out, C. diff can take over and colonise the gut

Clindamycin
Ciprofloxacin
Co-amoxiclav
Cephalosporin

Question 17

What infections are associated with diarrhoea in the immunocompromised?

Answer 17

CMV
Bacterial mycobacterium
Parasites

Question 18

What is dysentery?

Answer 18

Bloody diarrhoea