Vomiting and Malabsorption Part 2 Flashcards
How much fluid enters the duodenum daily and what volume of this reaches the colon?
9L fluid enters duodenum
1.5L gets to colon
<200ml lost in faeces
What features of the small intestine improve absorption?
Mucosal folds and villi
What does the small intestine excrete?
Water for fluidity/enzyme transport/absorption
Ions e.g. duodenal HCO3-
Defense mechanism against pathogens/harmful substances/antigens
What is the definition of chronic diarrhoea?
4 or more stools per day For more than 4 weeks
<1 week: acute diarrhoea
2 to 4 weeks: persistent diarrhoea
What are the three general causes of diarrhoea?
Motility disturbance
Active secretion
Malabsorption of nutrients
What are the types of motility disturbance?
Toddler Diarrhoea
Irritable Bowel Syndrome
What are the types of active secretion?
Acute Infective Diarrhoea
Inflammatory Bowel Disease
What are the types of malabsorption of nutrients (osmotic)?
Food Allergy
Coeliac Disease
Cystic Fibrosis
What is osmtoic diarrhoea?
Movement of water into the bowel to equilibrate osmotic gradient
Usually a feature of malabsorption:
- Enzymatic defect (eg. Secondary lactase deficiency)
- Transport defect ( eg glucose galactose transporter defect)
What is secretory diarrhoea?
Classically associated with toxin production from Vibrio cholerae and enterotoxigenic Escherichia coli
-In cholera, can lose 24L per day!
Intestinal fluid secretion predominantly driven by active Cl- secretion via CFTR
What are the components of a diarrhoea history?
Age at onset Abrupt/gradual onset Family history Travel history/local outbreaks Nocturnal defecation suggests organic pathology
What are the examinations/investigations carried out in diarrhoea?
Consider growth and weight gain of child
Faeces analysis
- Appearance
- Stool culture
- Determination of secretory vs. osmotic
How do you differentiate between osmotic and secretory diarrhoea?
OSMOTIC VS. SECRETORY
Osmotic:
- Small
- Large osmotic gap
- Low sodium, potassium and chloride
- Low pH
- Stool reducing substance positive
Secretory:
- Large
- Small osmotic gap
- High sodium, potassium and chloride
- High pH
- Stool reducing substance negative
What can cause fat malabsorption?
Pancreatic disease
Hepatobiliary disease
What are the types of pancreatic disease?
Diarrhoea due to lack of lipase and resultant steatorrhoea
Classically cystic fibrosis
What are the types of hepatobiliary disease?
Chronic liver disease
Cholestasis
What is Shwachman-Diamond syndrome?
Pancreatic insufficiency and bone marrow dysfunction
98% have neutropenia
What is coeliac disease?
“Gluten-sensitive enteropathy”
How does coeliac disease present?
Abdominal bloatedness Diarrhoea Failure to thrive Short stature Constipation Tiredness Dermatitis herpatiformis
More common in children with other autoimmune conditions like IDDM and first degree relatives
What serological tests are carried out for suspected coeliac disease?
Anti-tissue transglutaminase (high sensitivity)
Anti-endomysial ( high specificity)
Check Serum IgA
Concurrent IgA deficiency in 2% may result in false negatives
What is the gold standard for diagnosing coeliac disease?
Duodenal biopsy
Looks red and inflamed
What genetic testing may be used for coeliac disease?
HLA DQ2, DQ8
How may coeliac disease appear on histology?
Lymphocytic infiltration of surface epithelium,
Partial/total villous atrophy
Crypt hyperplasia
What are the ESPGHAN/BSPGHAN guidelines for diagnosing coeliac disease in children?
Symptomatic children
Anti TTG >10 times upper limit of normal (Anti-tissue transglutaminase
Positive anti endomysial antibodies
HLA DQ2, DQ8 positive
If all the above are present then diagnoses made without biopsy
If any of the above are not present then proceed to endoscopy
How is coeliac disease managed?
- Gluten-free diet for life
- Gluten must not be removed prior to diagnosis as serological and histological features will resolve
- In very young <2yrs, re-challenge and re-biopsy may be warranted
- Increased risk of rare small bowel lymphoma in untreated
Summary
Vomiting in infants and children can be due to GI and non GI causes.
Gastroesophageal reflux is common in infants and usually resolves with age
Coeliac disease is a common cause for malabsorption in children
In a well toddler, undigested vegetables in the stool suggests chronic non-specific ‘toddlers’ diarrhea and it improves with age.
