Severe acute diarrhoea

Question 1

Name a common cause of a single episode of diarrhoea?

Answer 1

Dietary indiscretion

Anxiety

Question 2

What is the significance of large-volume, watery stools?

Answer 2

There is always an organic cause

Question 3

What are the implications of blood diarrhoea?

Answer 3

Colonic disease

Rectal disease

Question 4

How long will an acute infective cause of diarrhoea last?

Answer 4

2-3 days

Question 5

When should Inflammatory bowel disease be considered?

Answer 5

Severe or prolonged symptoms

Question 6

What investigation is used to exclude infective causes of diarrhoea?

Answer 6

Stool culture

Question 7

Name the 2 broad categories of aetiology of diarrhoea, and differentiate between them

Answer 7

Organic cause (Stool >250g/d)
Functional cause

Question 8

Which features suggest an infective cause of diarrhoea?

Answer 8

Sudden onset of bowel frequency
Crampy abdominal pain
Fever

Question 9

Which features suggest an inflammatory cause of diarrhoea?

Answer 9

Bowel frequency
Loose, blood-stained stools
Pus

Question 10

Which features suggest steatorrhoea?

Answer 10

Pale, offensive stools that float
Loss of appetite
Weight loss

Question 11

What features suggest an organic cause of diarrhoea?

Answer 11

Nocturnal bowel frequency

Urgency

Question 12

What features suggest a functional cause of diarrhoea?

Answer 12

Frequent

Small-volume stools

Question 13

Define steatorrhoea

Answer 13

The presence of excess fat in faeces, due to fat malabsorption.

Produces a pale, offensive stool that floats.

Question 14

Name 3 common causes of diarrhoea

Answer 14

Gastroenteritis
Parasites/protozoa
Irritable bowel syndrome
Crohn's disease and Ulcerative Colitis
Coeliac disease
Colorectal cancer

Question 15

Name 3 less common causes of diarrhoea

Answer 15

Microscopic colitis
Chronic pancreatitis
Bile salt malabsorption
Laxative abuse
Lactose intolerance
Diverticular disease
Overflow diarrhoea
C. difficile

Question 16

Name 2 non-GI or rare causes of diarrhoea

Answer 16

Thyrotoxicosis
Autonomic neuropathy
Addison's disease
Ischaemic colitis
Gastrinoma e.g. Zollinger-Ellison syndrome
Carcinoid (neuroendocrine tumours)

Question 17

Name 3 drugs that cause diarrhoea

Answer 17

Antibiotics
Laxatives
NSAIDs
PPI
Alcohol
Psychotropic drugs: SSRIs etc.

Question 18

State the different types of pathophysiology in diarrhoea

Answer 18

Osmotic
Secretory
Inflammatory
Abnormal motility

Question 19

Describe the pathophysiology of osmotic diarrhoea

Answer 19

Presence of large quantities of hypertonic substances in the gut lumen ➔ fluid is drawn into the lumen

Question 20

Describe the pathophysiology of secretory diarrhoea

Answer 20

Active intestinal secretion of fluid and electrolytes (Cl- secretion into lumen), and decreased absorption

Question 21

Outline the causes of osmotic diarrhoea

Answer 21

Ingestion of non-absorbable substances e.g. MgSO4
General malabsorption
Specific absorptive defects e.g. Disaccharidase deficiency

Question 22

Outline the common causes of secretory diarrhoea

Answer 22

Enterotoxins e.g. E. coli, cholera, C. difficile
Hormones e.g. VIPoma (Vasoactive intestinal peptide)
Bile salts following ileal resection
Fatty acids following ileal resection
Some laxatives

Question 23

Describe the pathophysiology of inflammatory diarrhoea

Answer 23

Damage to intestinal mucosal cells ➔ fluid and blood loss, and defective fluid and electrolyte absorption

Question 24

Outline the common causes of inflammatory diarrhoea

Answer 24

Infective causes e.g. Shigella ➔ dysentry

Inflammatory bowel disease

Question 25

Name 2 medical conditions that cause diarrhoea due to abnormal motility

Answer 25

Diabetic diarrhoea Hyperthyroid diarrhoea Post-vagotomy diarrhoea

Question 26

What clinical features are associated with acute diarrhoea?

Answer 26

Fever Abdominal pain Vomiting Dehydration and hypokalaemia (severe)

Question 27

Which patients are particularly susceptible to dehydration secondary to diarrhoea?

Answer 27

Very young | Very old

Question 28

What is the duration of acute diarrhoea?

Answer 28

Under 2 weeks

Question 29

Name 3 considerations if bloody diarrhoea occurs

Answer 29

``` Campylobacter Shigella/salmonella E. coli IBD Colorectal cancer Colonic polyps Ischaemic colitis ```

Question 30

Name 2 consideration if mucus appear in diarrhoea

Answer 30

Irritable bowel syndrome Colorectal cancer Polyps

Question 31

Name 2 considerations if frank pus occurs

Answer 31

IBD Diverticulitis Fistula/abscess

Question 32

Name 2 considerations for explosive diarrhoea

Answer 32

Cholera Giardia Yersinia Rotavirus

Question 33

When are investigations necessary for a presentation of diarrhoea?

Answer 33

If the diarrhoea has lasted more than 1 week

Question 34

What initial investigations should be taken in cases of diarrhoea?

Answer 34

Stool culture: bacterial pathogens, ova, cysts, parasites, C. difficile FBC, CRP, U&E, TSH Coeliac serology

Question 35

Following initial investigations for diarrhoea, what investigations should occur next?

Answer 35

Sigmoidoscopy Rectal biopsy (Colonoscopy if necessary)

Question 36

What is the maximum duration of viral/bacterial infective diarrhoea?

Answer 36

7-10 days

Question 37

What is the most likely cause of diarrhoea if duration exceeds 10 days?

Answer 37

Inflammatory bowel disease

Question 38

Outline the management of acute diarrhoea

Answer 38

Treat underlying cause Food handlers should avoid work till stool samples -ve Oral rehydration Otherwise, 0.9% saline + 22mmol K+ per L Codeine phosphate or Loperamide after each loose stool Avoid antibiotics

Question 39

Why is Codeine phosphate or Loperamide taken during diarrhoea?

Answer 39

Anti-motility drugs: decrease the frequency of passing stool

Question 40

Why is colitis a contraindication for Codeine phosphate or Loperamide?

Answer 40

Both may precipitate toxic megacolon

Question 41

What can be given in Antibiotic-associated diarrhoea?

Answer 41

Probiotics (e.g. Lactobacilli)

Question 42

Describe the mechanism of action of Anti-motility drugs (Codeine phosphate and Loperamide)

Answer 42

Bind to opioid mu-receptors ➔ slow motility and increase anal tone

Question 43

What are the 3 commonest causes of gastroenteritis?

Answer 43

Norovirus Rotavirus (children) Contaminated food (Shigella, S. aureus, Salmonella etc.)

Question 44

How long does norovirus infection last?

Answer 44

Short-duration: 12-60 hours

Question 45

What is the typical presentation of norovirus infection?

Answer 45

Fever Nausea Projectile vomiting Watery diarrhoea

Question 46

Describe the management of norovirus infection

Answer 46

Supportive management of fluids and electrolytes. Norovirus is self-limiting.

Question 47

What measure should be taken if a norovirus outbreak occurs on the ward?

Answer 47

Healthcare quarantine, due to its highly infectious (faecal-oral and aerosol) nature up to 48hr after resolution.

Question 48

What is the typical presentation of rotavirus infection?

Answer 48

Vomiting Watery diarrhoea Hyperactive bowel sounds (Adults have much milder symptoms)

Question 49

What intervention has reduced NaV due to rotavirus by 50%?

Answer 49

Rotavirus vaccinations - given to infants alongside other routine vaccinations.

Question 50

Define traveller's diarrhoea

Answer 50

Any diarrhoea experience within the first two weeks of travelling abroad.

Question 51

What proportion of travellers experience traveller's diarrhoea?

Answer 51

60%

Question 52

Why is Clostridium difficile difficult to contain in healthcare settings?

Answer 52

It is extremely contagious and resilient to both heat and alcohol-gel.

Question 53

What investigation should be taken in suspected C. diff infection?

Answer 53

Stool culture for C. diff enterotoxin

Question 54

What is the initial treatment for C. diff infection?

Answer 54

Stop causative antibiotic | If symptomatic, give metronidazole up to 400mg/8h PO for 10d max

Question 55

What can be given in severe C. diff infections?

Answer 55

Vancomycin 125mg/6hr PO