malabsorption

Question 1

what happens when you resect the terminal ileum

Answer 1

100cm=steatorrhea from insufficient bile acids

Question 2

What happens to CHOs that are not absorbed? How is this utilized diagnostically?

Answer 2

undergo bacterial degradation in colon, forming H2, CO2, short chain fatty acids. Basis of H2 breath test small bowel bacterial overgrowth

Question 3

Protein maldigestion: could it be caused by hypochlorhydria? What is the clinical consequence?

Answer 3

No, you can resect stomach and not have protein digestion problems. Hypoalbuminemia resulting in edema

Question 4

Malabsorption is usually defined in terms of what? What qualitative test can be done to determine this?

Answer 4

fat (steatorrhea). Sudan stain (low sens, high spec) or 72 hour fecal fat

Question 5

D xylose test: basis? abnormal in? confounders?

Answer 5

d-xylose administered and urinary excretion measured. Should be passively absorbed in small bowel and >5gm excreted in urine. If <5gm you have absorption problem. Confounders: renal insufficiency, bacterial overgrowth which metabolizes d-xylose

Question 6

Schilling’s test: what does it assess? What can cause it to be abnormal? What confounders are there?

Answer 6

B12 metabolism. Ileal dysfxn, pernicious anemia, pancreatic insufficiency (R protein not split from IF by pancreas enzyme in severe pancreatitis), bacterial overgrowth (metabolize B12 and produce folate)

Question 7

Duodenal drainage: normal numbers? chronic pancreatitis numbers? obstruction (CA) numbers?

Answer 7

bicarb>90, volume>100.
Chronic pancreatitis: (low bicarb) bicarb100
obstruction: (low volume) bicarb>90, vol<100

Question 8

what conditions have pathognomonic lesions?

Answer 8

whipples (PAS + macrophages), Lymphoma, intestinal lymphangiectasia, abetalipoproteinemia