Chronic diarrhoea (and malabsorption) Flashcards
How much fluid enters the duodenum ever day?
9 litres
- 5 litres to the colon
- 200 mls lost in the faeces
What are some of the secretory components of the small intestine? (3)
- Water for fluidity/enzyme transport/absorption
- Ions e.g. duodenal HCO3-
- Defence mechanism against pathogens/harmful substances/antigens
what is chronic diarrhoea?
4 or more stools per day for more than 4 weeks
motility disturbance causes?
Toddler Diarrhoea - increased transit in the SI - food not digested
Irritable Bowel Syndrome - abdo pain after eating, urge to go to toilet
Active secretion causes?
Acute Infective Diarrhoea
Inflammatory Bowel Disease
Malabsorption of nutrients (osmotic) causes?
Food Allergy
Coeliac Disease
Cystic Fibrosis
What is osmotic diarrhoea caused by?
Movement of water into the bowel to equilibrate osmotic gradient
Enzymatic defect diarrhoea - example (osmotic)
lactose intolerance
Transport defect diarrhoea - example (osmotic)
glucose-galactose malabsorption or congenital chloride diarrhoea.
Secretory types of diarrhoea?
toxin production
- from Vibrio cholerae and enterotoxigenic Escherichia coli
In cholera, can lose 24L per day!
In secretory diarrhoea, what is inertial fluid secret driven by
Cl- secretion via CFTR
Nocturnal defecation suggests?
organic pathology
coeliac symptoms often begin with?
the introduction of food
CMPI symptoms introduced with?
cow’s milk
Sucrase-isomaltase with introduction of?
fruits and juices.
features of osmotic diarrhoea
low stool volume - responds to fasting
- osmolality high
Secretory diarrhoea and electrolytes
electrolytes are high , sodium potassium , chloride
Fat malabsorption is seen in pancreatic disorders - why? give examples
?
Diarrhoea due to lack of lipase and resultant steatorrhoea
- Classically cystic fibrosis
Hepatobiliary Disease causing fat malabsorption examples?
Chronic liver disease
Cholestasis
What is Shwachman-Diamond syndrome
Pancreatic insufficiency and bone marrow dysfunction. 98% have neutropenia.
Most common cause of malabsorption in children?
coeliac disease
(exposed to solids)
- Gluten-sensitive enteropathy
Coeliac disease features and symptoms
Abdominal bloatedness Diarrhoea Failure to thrive Short stature Constipation Tiredness Dermatitis herpatiformis IDDM and first relatives
Screening tests for coeliac disease? (4)
- Anti-tissue transglutaminase (high sensitivity)
- Anti-endomysial ( high specificity)
- Check Serum IgA
- Concurrent IgA deficiency in 2% may result in false negatives
Gold standard test for coeliac disease?
duodenal biopsy
Genetic testing - genes to look for?
HLA DQ2, DQ8
Features of coeliac histology?
Lymphocytic infiltration of surface epithelium, partial /total villous atrophy,
crypt hyperplasia
what guidelines can you use?
ESPGHAN /BSPGHAN
ESPGHAN /BSPGHAN guidelines are? (making a diagnosis without a biopsy) - what 4 features do you need
- Symptomatic children
- Anti TTG >10 times upper limit of normal
- Positive anti endomysial antibodies
- HLA DQ2, DQ8 positive
Treatment of Coeliac disease.. what is there a small risk of?
- 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 (auto immune enteritis)
Increased risk of rare small bowel lymphoma in untreated
