Malabsorption and small intestinal disease Flashcards
What are the main functions of the small intestine?
Digestion, absorption, endocrine and neural control and barrier functions
List 4 ways in which the small intestine acts as a barrier against pathogens
gut associated lymphoid tissue
immune sampling
monitor pathogen presence
translocation of bacteria
What is the average adult length of the small intestine and what age is this achieved by?
2.5-4.5m
11 years old
What makes up the toxic environment of the small intestine? what is the result of this?
bile salts, IgA, enzymes
low bacterial population
Why is digestion controlled?
to avoid osmotic shifts
What constituents are proteins broken down to and what enzyme controls this?
oligopeptides and amino acids
trypsin
What are the symptoms of malabsorption?
weight loss
increased appetite in severe malabsorption
steatorrhoea
Briefly describe steatorrhoea - cause, appearance etc
malabsorption of fat which leads to fat in the faeces giving a very high content of fat in the stool. This results in a less dense, pale, foul smelling stool which floats. Often complaints about leaving an oily mark.
What is scleroderma an indicator effect and what can this effect in the gut?
systemic sclerosis
motility
What illnesses can clubbing and aphthous ulceration be an indicator of?
crohns and coeliac
What is the cutaneous manifestation of coeliac disease called?
dermatitis herpetiforms
What is dermatitis herpetiforms like?
intensely itchy found at elbows, knees, shoulders and scalp with blistering
What is dermatitis herpetiforms due to?
IgA deposit in the skin
Are there more investigations for structure or function of the gut?
structure
What are some tests of structure of the small bowel?
endoscopy - biopsy
barium meal, MRI enterography, capsule enterography, CT, white cell scan
What test can be done for suspected bacterial overgrowth?
H2 breath test
What is villous atrophy associated with?
absorption disruption
What is coeliac disease due to?
sensitivity to giadin in gluten
What foods is gluten found in?
wheat, barley, rye - not in oats but oats are usually made in contact with the others so are common to be contaminated so coeliacs usually eat special oats
An inflammatory response is produced via what antibody in coeliac disease?
tissue transglutaminase
List the steps of the pathology behind coeliac disease
After inflammatory response there is also villous atrophy be it partial or subtotal, increased intra epithelial lymphocytes
How is coeliac disease diagnosed?
Via distal duodenal biopsy and serology - anti tissue transglutaminase and anti endosymal IgA
How is coeliac disease treated?
remove gluten from diet - refer to dietitian
List some associated conditions with coeliac disease
autoimmune hepatitis, primary biliary cirrhosis, autoimmune thyroid disease, autoimmune gastritis, downs syndrome, dermatitis herpetiforms
List some complications of coeliac disease
small bowel lymphoma, colon cancer, oesophageal cancer, small bowel adenocarcinoma, refractory coeliac disease
Inflammatory causes of malabsorption
coeliac disease
crohns
Infection causes of malabsorption
tropical sprue
HIV
gardia lambia - parasite found in infected water
Pancreatic causes of malabsorption
chronic pancreatitis, cystic fibrosis
What is whipples disease?
caused by tropheryma whippeli effects middle aged men weight loss, malabsorption, abdo pain skin, brain, joints and cardiac treated with antibiotics
Infiltration causes of malabsorption?
amyloid
Impaired motility causes of malabsorption?
systemic sclerosis
diabetes
pseudo obstruction
Iatrogenic causes of malabsorption?
radiation
short bowel syndrome
gastric surgery
