7 - Malabsorption

Question 1

four steps of fat absorption

Answer 1

pancreatic, biliary, intestinal, intracellular

Question 2

what is the most complicated thing to absorb in GI tract?

Answer 2

fat - not water soluble

Question 3

presentation of malabsorption

Answer 3

wt loss, steatorrhea, vitamin def, malnutrition

Question 4

malabsorption tests

Answer 4

fecal fat excretion
d-xylose absorption
b12 absorption
small bowel biopsy
small bowel xray
breath tests (for bile salts, etc)

Question 5

tests that are NOT good for malabsorption (2)

Answer 5

serum carotene

qualitative fecal fat

Question 6

Schilling’s test

Answer 6

B12 absorption - serially w/ different added factors
1 - just b12
2 - + intrinsic factor (r/o pernicious anemia)
3 - + abx (r/o bacterial overgrowth)
4 - + trypsin (r/o pancreatic insufficiency)

Question 7

causes of pancreatic insufficiency

Answer 7

chronic pancreatitis
pancreatic resection
pancreatic CA
CF
zollinger ellison

Question 8

causes of insufficient bile salt activity

Answer 8

biliary obstruction
blind loop syndrome
ileal dz or resection
zollinger ellison

Question 9

endoscopy findings in celiac dz

Answer 9

mosaic pattern, scalloping, absent villi

Question 10

what molecule is the immune response in celiac due to?

Answer 10

alpha gliadin (breakdown product of gluten)

Question 11

best serologic tests for celiac

Answer 11

enndomesial antibody IgA and tissue transglutaminase IgA

Question 12

people who are “allergic” to mushrooms have what condition?

Answer 12

trehalase deficiency (a disaccharidase)

Question 13

bacterial overgrowth - how does it cause malabsorption

Answer 13

bacteria compete for luminal contents

Question 14

what conditions presdispose a patient to bacterial overgrowth?

Answer 14

diverticulosis, motor abnormalities of small bowel, surgical bypass, etc