Vomiting and Malabsorption in Children 2 Flashcards
How much fluid:
- enters duodenum
- colon
- lost in faeces
- 9L fluid enters duodenum
- 1.5L gets to colon
- <200ml lost in faeces
- (rest gets reabsorbed in small intestine)
What are essential secretory compoents?
- Water for fluiditiy/enzyme transport/absorption
- Ions such as duodenal bicarbonate
- Defect mechanism against pathogens/harmful substances/antigens
Chronic diarrhoea - definition
- 4 or more stools per day for more than 4 weeks
Chronic diarrhoea - classification
- <1 week
- Acute diarrhoea
- 2 to 4 weeks
- Persistent diarrhoea
- >4 weeks
- Chronic diarrhoea
Chronic diarrhoea - aetiology
- 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
Osmotic diarrhoea - pathology
Occurs when movement of water into the bowel to equilibrate osmotic gradient
What is osmotic diarrhoea usuallt a feature of?
Usually a feature of malabsorption:
- Enzymatic defect (such as secondary lactose deficiency)
- Transport defect (such as glucose galactose transporter defect)
What are examples of the following which can cause osmotic diarrhoea:
- enzymatic defect
- transport defect
- Enzymatic defect (such as secondary lactose deficiency)
- Transport defect (such as glucose galactose transporter defect)
Osmotic diarrhoea is the mechanism of action of what drugs?
This is the mechanism of action ofluctulose/movicol
Osmotic diarrhoea - treatment
- Remission with removal of causative agent
Secretory diarrhoea - aetiology
Classifically associated with toxin production from Vibrio Cholerae and enterotoxigenic E-coli
Intestinal fluid secretion predominantly driven by active chloride secretion via CFTR
What are the different kinds of diarrhoea?
Osmotic diarrhoea
Secretory diarrhoea
Describe the clinical approach for chronic diarrhoea?
- 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
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

Fat malabsorption - causes
- Pancreatic disease
- Due to lack of lipase and resultant steatorrhea
- Classically cystic fibrosis
- Hepatobiliary disease
- Chronic liver disease
- Cholestasis
What of the following can cause fat malabsorption:
- pancreatic disease
- hepatobiliary disease
- Pancreatic disease
- Due to lack of lipase and resultant steatorrhea
- Classically cystic fibrosis
- Hepatobiliary disease
- Chronic liver disease
- Cholestasis
Coeliac disease - epidemiology
(prevalence)
- 1% western population
Coeliac disease - risk factors
- Genetics
- HLA-DQ2, DQ8
What genes have been linked to coeliac disease?
- HLA-DQ2, DQ8
Coeliac disease - presentation
- Abdominal bloatedness
- Diarrhoea
- Failure to thrive
- Short stature
- Constipation
- Tiredness
- Dermatitis herpatiformis
- More common in children with other autoimmune conditions like diabetes
Coeliac disease - investigations
- 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
What serological screens should be done for coeliac disease?
- Anti-tissue transglutaminase (high sensitivity)
- Anti-endomysial (high sensitivity)
- Check serum IgA
What are the guidelines for when coeliac disease diagnosis can be made without biopsy?
- 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
Coeliac disease - treatment
- Gluten free diet for life
- Do not remove gluten prior to diagnosis
Coeliac disease - complications
- Increased risk of rare small bowel lymphoma in untreated