Diarrhoea

Question 1

definition of acute chronic & persistent diarrhoea

Answer 1

chronic - diarrhoea 4 or more times a day for > 4 weeks

acute- <1 week

persistent- 2-4weeks

Question 2

types of diarrhoea & their causes?

Answer 2

• motility- motility disturbance
• osmotic -malabsorption of nutrients
• secretory- active secretion
• inflammatory

Question 3

key features of osmotic diarrhoea + examples

Answer 3

• linked with malabsorption of nutrients
• examples
  
  • Food allergy
  • Coeliac
• water flows out into bowel to equilize the osmotic agent

Question 4

certain laxatives adopt the same mechanism of action as osmotic diarrhoea. Which ones are they?

Answer 4

isotonic / osmotic –> lactulose or movicol

Question 5

clinical remission of osmotic diarrhoea is achieved by doing what?

Answer 5

avoidance of causative agent

Question 6

in osmotic diarrhoea, what are the main food groups that cause malabsorption?

Answer 6

• carbohydrates –> particularly lactose
• fat
  
  • this is due to underlying pancreatic/ liver disease

Question 7

what is secretory diarrhoea classically associated with?

Answer 7

• Toxin production by cholera / enterotoxigenic E.Coli
  
  • fluid secretion is stimulated by secretion of chloride by CFTR
• IBD

Question 8

main causes of motility diarrhoea?

Answer 8

• toddler’s diarrhoea
• IBS

Question 9

what is inflammatory diarrhoea due to?

Answer 9

• intestinal damage
• cytokines cause secretion
• protein exudate crosses the inflamed epithelium

Question 10

outline difference between osmotic and secretory in terms of:

• stool volume
• repsonse to fasting
• stool reducing substance

Answer 10

• stool volume
  
  • osmotic - small
  • secretory- large
• response to fasting
  
  • osmotic- diarrhoea stops
  • secretory- continues
• stool reducing substance (unabsorbed sugars)
  
  • osmotic- positive
  • secretory- negative

Question 11

how does coeliac present in a child?

Answer 11

FTT, non-specific abdo pain, vomiting, diarrhoea, irritability, anaemia, constipation

Question 12

what is there a risk of if coeliac is left untreated?

Answer 12

small bowel lymphoma

Question 13

Ix for coeliac?

Answer 13

• Anti endomysial IGA
• Anti-TTG

if positive, proceed to biopsy

Question 14

if the child is under 2, what should be done?

Answer 14

re-challenge and re-biopsy later on