Malabsorption Syndromes CIS - Darrow Flashcards
chronic diarrhea
4 weeks
watery - pourable - osmotic or secretory
fatty - fat on sudan stain
inflammatory
watery diarrhea
pourable
osmotic or secretory
secretory - consider bile acids**
osmotic - carbohydrates
sudan stain
for fat
fatty diarrhea
steatorrhea
malabsorpion
maldigestion
inflammatory diarrhea
blood and puss
positive hemoccult and fecal leukocytes
niacin deficiencys
3 Ds
diarrhea, dermatitis, dementia
carcinoid syndrome
order urine for 5 hydroxy indol acetic acid
tryptophan shunted to serotonin
-not available for niacin synthesis
so you see the 3 Ds
osmotic gap >100
osmotic watery chronic diarrhea**
from carbs
lactase deficiency
osmotic gap <50
interrupts sleep as well**
secretory watery chronic diarrhea**
from bile acids, neuroendocrine tumor, increased motility, villous adenoma, microscopic colitis, infections
malabsorption
fatty chronic steatorrhea
celiac, tropical sprue, short bowel, lymph obstruction, tropheryma whipplei
maldigestion
fatty chronic steatorrhea
pancreatic insufficiency
bile acid deficiency
bacterial overgrowth - deconjugation of bile acid
inflammatory chronic diarrhea
blood and pus
positive hemoccult and fecal leukocytes
fever
CMV, herpes, c dif, campylovacter, balantidium coli (pigs), colon cancer, lymphoma
Case 36yo M crohns watery diarrhea
- history of bloody diarrhea with steatorrhea
- cleared with infliximab
sore on right leg
sudan stain negative hemoccult/leukocytes negative stool for O and P negative stool Na 90 stool K 50 stool osmolality 290
treatment?
osm gap - 290 - 2(90 + 50)
290-280 = 10
pyodermic gangrenosum
with inflammatory bowel disease
stool osmotic gap calculation
290 − 2 x (stool Na + stool K)
The 290 is the value of the stool osmolality
secretory diarrhea causes
bile acids increased motility infection villous adenoma neuroendocrine tumors microscopic colitis
less than 100cm of ileal involvement or resection**
liver able to keep up with bile acid synthesis
enough bile acid for fat absorption
bile lost to colon produces secretory diarrhea - so it needs to be bound to control diarrhea** - bile acid binding agent
greater than 100cm of ileal involvement**
not enough micelle formation - steatorrhea
so need low fat diet, vit replacement , medium chain triglycerides**
Case 45yo M right kidney stone and gallstone on CT
- hemoglobinuria, hemosiderinuria, LDH elevation
- iron deficiency anemia
- prior DVT of left arm
- bowel resection 2 months ago bc of blood clot of small intestine
steatorrhea, weight loss, easy bruising, back pain, paresthesias
hemoglobinuria - hemolysis intravascular
venous and arterial blood clots - paroxysmal nocturnal hemoglobinuria
stone formation - no bile acids and hemolysis
kidney stones - FA bind calcium - increased oxalate absorption
short bowel syndrome
malabsorption
Case 25yo F recurrent loose stool when stressed, no pain while sleeping
sudan 3 negative
tx - irritable bowel syndrome
change in bowel flora
3lbs in gut
increased fecal serine potease activity
36yo F weakness and fatigue and pruritic rash, occasional diarrhea
skin biopsy - granular deposits if IgA
rash - dermatitis herpetiformis
-IgA deposits in the rash
IgA in bowel - celiac**
IgA diseases
deficiency - bronchitis, diarrhea, transfusion rxn
GI disease - celiac
renal disease - IgA nephropathy or henoch schonlein
Case 46yo F, depression, fatigue, weight loss, miscarriages, hypothyroid, IBS takes Ca with Vit D, iron deficiency, sudan 3 positive
what lab test to order?
sudan 3 - steatorrhea
celiac**
so test to order - IgA tTG**
IgA tTG
test for celiac
fat steatorrhea
malabsorption - celiac disease
celiac disease
malabsorption steatorrhea
can have dermatitis herpetiformis
- elevated liver and pancreatic enzymes
- miscarriages
- iron deficiency
- DM I
- addisons
- osteopenia
- steatorrhea
- weight loss
- villous atrophy of mucosa
celiac disease
osteoporosis and malignancy (B cell lymphomas) are complications
genetics of celiac
HLA-DQ2 and DQ8
MHC class II molecules
Ag presentation to CD4 cells
production if IgA against EMA and tTG**
celiac disease
gluten free diet that get worse all of a sudden
-think B cell lymphoma
Case 66yo M diabetic
- nonerosive atrophic gastritis
- bloating and chronic watery diarrhea
- weight loss
- anemia macrocytosis
stool osmolality 350
stool Na 30
stool K 75
stool pH 3.5
sudan positive
pernicious anemia
stool osm gap
350 - 2(30 + 75) = 140
osmotic diarrhea**
-carbohydrates
low stool pH -
low stool pH
osmotic diarrhe
-carb breakdown by colonic bacteria - releases free fatty acids that are organic anions
bacterial overgrowth
watery diarrhea** - due to osmotic load of unabsorbed carbohydrates
-proteases from bugs destroy brush border diasaccharidases
lower pH of stool less than 5 because of release of free-fatty acids with carb breakdown
bacteria consume B12 and nutrients - deconjugate bile acids**
results in malabsorption of fat with steatorrhea - lack of micelle formation
-results in secretory diarrhea**
to prove bacterial overgrowth
d-C14 xylose breath test
gut anaerobes metabolize oral d-xylose to CO2 measured in expired air at 30 minutes with small intestine bacterial overgrowth
also - hydrogen breath test
- give lactose and measure breath hydrogen
- 90 minutes - will have >20ppm hydrogen - earlier peak indicates bacterial overgrowth
Case 45yo M asthenic, HIV positive, fever, arthralgia, diarrhea, weight loss, blurred vision, lethargy, back pain, jerking paresthesias
murmurs, pedal edema
PAS positive positive macrophages
rules of 3s - fever of undetermined origin
PAS positive macrophages - whipple disease - tropheryma whippeli from MAC
tropheryma whippelii
multiple organ involvement
Case 30yo F watery diarrhea 6 weeks duration, weight loss
stool osmolar gap 200
fasted didnt help
not osmotic - bc fasting didnt help
but stool osm gap suggests secretory
taking laxative - Mg
