Malabsorption Flashcards
define malabsorption?
defective mucosal absorption caused by defective luminal digestion. mucosal disease, and structural disorders
name common causes of malabsorption?
coeliac disease, crohns disease, post infectious, biliary obstruction and cirrhosis
what are some uncommon causes of malabsorption?
pancreatic cancer, parasites, bacterial overgrowth, drugs and short bowel
Name some digestive causes of protein malabsorption?
gastrectomy (poor mixing), exocrine pancreatic insufficiency, trypsinogen deficiency, congenital deficiency of intestinal enterokinase
what are absorptive causes of protein malabsorption?
celiac diseases
short bowel syndrome
jejunoileal bypass
defects in AA transporters
What are the 4 stages of fat absorption and where do each occur
Lipolysis (pancreas), micellar solubilization with bile acid (Liver), absorption (jejunal mucosa, delivery (lymphatics)
What are the digestive causes of carbohydrate absorption?
severe pancreatic insufficiency (alpha-amylase deficiency)
What are the absorptive causes of carbohydrates malabsorption?
primary or acquired lactase deficiency, post infectious lactase deficiency, celiac disease, crohns disease
Why is vitamin B12 difficult to abosrb?
atropic gastritic, deficiency of gastric intrinsic factor, pancreatic insufficiency, illeal crohns disease/resection
why do we not absorb enough folic sometimes?
caused by diseases affecting the proximal small bowel, celiac disease/ whipple
alcoholism
Why are fat soluable vitamics ADEK difficult to absorb sometimes?
anything that disrupts fat absorption will lead to deficiency
What is coeliac disease?
exposure to wheat, barley, or rye induces a characteristic mucosal lesion
what mucosal activity is activated in coeliac disease
t lymphocytes cytokines
What are the symptoms of coeliac disease?
weight loss, diarrhoea, excess flatus and abdominal discomfort
how do you diagnose
IGA anti tissue transglutaminase test tTGA biopsy confirmation
