Vomiting and Malabsorption in Children 2

Question 1

How much fluid:

• enters duodenum
• colon
• lost in faeces

Answer 1

• 9L fluid enters duodenum
• 1.5L gets to colon
• <200ml lost in faeces
• (rest gets reabsorbed in small intestine)

Question 2

What are essential secretory compoents?

Answer 2

• Water for fluiditiy/enzyme transport/absorption
• Ions such as duodenal bicarbonate
• Defect mechanism against pathogens/harmful substances/antigens

Question 3

Chronic diarrhoea - definition

Answer 3

• 4 or more stools per day for more than 4 weeks

Question 4

Chronic diarrhoea - classification

Answer 4

• <1 week
  
  • Acute diarrhoea
• 2 to 4 weeks
  
  • Persistent diarrhoea
• >4 weeks
  
  • Chronic diarrhoea

Question 5

Chronic diarrhoea - aetiology

Answer 5

• Motility disturbance
  
  • Toddler diarrhoea
  • Irritable bowel syndrome
• Active secretion (secretory)
  
  • Acute infective diarrhoea
  • Inflammatory bowel disease
• Malabsorption of nutrients (osmotic)
  
  • Food allergy
  • Coeliac disease
  • Cystic fibrosis

Question 6

Osmotic diarrhoea - pathology

Answer 6

Occurs when movement of water into the bowel to equilibrate osmotic gradient

Question 7

What is osmotic diarrhoea usuallt a feature of?

Answer 7

Usually a feature of malabsorption:

• Enzymatic defect (such as secondary lactose deficiency)
• Transport defect (such as glucose galactose transporter defect)

Question 8

What are examples of the following which can cause osmotic diarrhoea:

• enzymatic defect
• transport defect

Answer 8

• Enzymatic defect (such as secondary lactose deficiency)
• Transport defect (such as glucose galactose transporter defect)

Question 9

Osmotic diarrhoea is the mechanism of action of what drugs?

Answer 9

This is the mechanism of action ofluctulose/movicol

Question 10

Osmotic diarrhoea - treatment

Answer 10

• Remission with removal of causative agent

Question 11

Secretory diarrhoea - aetiology

Answer 11

Classifically associated with toxin production from Vibrio Cholerae and enterotoxigenic E-coli

Intestinal fluid secretion predominantly driven by active chloride secretion via CFTR

Question 12

What are the different kinds of diarrhoea?

Answer 12

Osmotic diarrhoea

Secretory diarrhoea

Question 13

Describe the clinical approach for chronic diarrhoea?

Answer 13

• History
  
  • Age of onset
  • Abrupt/gradual onset
  • Family history
  • Travel history/local outbreaks
  • Nocturnal defecation is always pathological
• Consider growth and weight of child
• Faeces analysis
  
  • Appearance
  • Stool culture
  • Determination of secretory vs osmotic

Question 14

Compare and contrast osmotic and secretory diarrhoea in terms of:

• stool volume
• response to fasting
• stool osmolarity
• osmotic gap
• stool sodium
• stool potassium
• stool chloride
• stool pH
• stool reducing substance

Answer 14

Question 15

Fat malabsorption - causes

Answer 15

• Pancreatic disease
  
  • Due to lack of lipase and resultant steatorrhea
  • Classically cystic fibrosis
• Hepatobiliary disease
  
  • Chronic liver disease
  • Cholestasis

Question 16

What of the following can cause fat malabsorption:

• pancreatic disease
• hepatobiliary disease

Answer 16

• Pancreatic disease
  
  • Due to lack of lipase and resultant steatorrhea
  • Classically cystic fibrosis
• Hepatobiliary disease
  
  • Chronic liver disease
  • Cholestasis

Question 17

Coeliac disease - epidemiology

(prevalence)

Answer 17

• 1% western population

Question 18

Coeliac disease - risk factors

Answer 18

• Genetics
  
  • HLA-DQ2, DQ8

Question 19

What genes have been linked to coeliac disease?

Answer 19

• HLA-DQ2, DQ8

Question 20

Coeliac disease - presentation

Answer 20

• Abdominal bloatedness
• Diarrhoea
• Failure to thrive
• Short stature
• Constipation
• Tiredness
• Dermatitis herpatiformis
• More common in children with other autoimmune conditions like diabetes

Question 21

Coeliac disease - investigations

Answer 21

• Serological screens
  
  • Anti-tissue transglutaminase (high sensitivity)
  • Anti-endomysial (high sensitivity)
  • Check serum IgA
• Duodenal biopsy for histology
  
  • Gold standard
• Genetic testing
  
  • HLA DQ2, DQ8

Question 22

What serological screens should be done for coeliac disease?

Answer 22

• Anti-tissue transglutaminase (high sensitivity)
• Anti-endomysial (high sensitivity)
• Check serum IgA

Question 23

What are the guidelines for when coeliac disease diagnosis can be made without biopsy?

Answer 23

• Espghan/Bspghan guidelines
• If ALL of these features are present do not need
  
  • Symptomatic children
  • Anti TTG>10x upper limit of normal
  • Positive anti-endomysial antibodies
  • HLA DQ2, DQ8 positive

Question 24

Coeliac disease - treatment

Answer 24

• Gluten free diet for life
  
  • Do not remove gluten prior to diagnosis

Question 25

Coeliac disease - complications

Answer 25

* Increased risk of rare small bowel lymphoma in untreated