Darrow Malabsorption and Diarrhea (CIS) Flashcards
(25 cards)
chronic diarrhea lasts how long?
at least 4 weeks
secretory diarrhea
osm gap?
from bile acids***
osmotic gap <50
-interrupts sleep!!***
also:
-neuroendocrine tumors (carcinoid, VIP)
increased motility (postvagotomy, DM, meds, IBS)
villous adenoma
microscopic colitis
infections
osmotic diarrhea
from carbohydrates (sugar)! these create osmolality
-lactase deficiency
sorbitol ingestion
poorly absorbed salts
osmotic gap >100,
relieved by fasting
Fatty diarrhea
2 types
Malabsorption (celiac, tropical sprue, short bowel, lymphatic obstruction, mesenteric ischemia, Tropheryma whipplei)
-don’t absorb fats
Maldigestion (pancreatic insufficiency, bile acid deficiency** or deconjugation/bacterial overgrowth***)
- bile acids can be deficient b/c of obstruction or b/c the bile acids are being digested by bacteria in the small intestine
- can’t breakdown the fat/FA’s to form chylomicrons
Bulky, floating stool = steatorrhea
blood and pus inflammatory diarrhea
positive hemoccult and fecal leukocytes
painful, and may be febrile:
From infections (CMV, Herpes including Kaposi’s, E. histolytica, Balantidium coli (pigs)***, C. diff, Campylobacter, Aeromonas, Plesimonas, Mycobacteria, Shistosoma (eosinophilia), IBD, ischemic and radiation colitis, colon cancer, and lymphoma.
niacin deficiency (
diarrhea
dermatitis
dementia
delayed diagnosis
death
carcinoid syndrome
find via urine diagnosis–> 5-hydroxy acetic acid
tryptophan is shunted to serotonin and is not available for niacin production.
present with niacin deficiency
stool osmolality calculation
2x (NA + K)
Less than ___ cm of ileal involvement or resection – liver able to keep
up with bile acid synthesis, so enough bile acid for fat absorption.
The bile lost to the colon produces a secretory diarrhea, so it needs to
be bound to control the diarrhea.
100 cm
Greater than ___ cm of ileal involvement – not enough micelle
formation (steatorrhea), so need low fat diet, vitamin replacement,
and medium-chained triglycerides.
100 cm
horrendous bile acid malabsorption
A 45 y/o male presents with a new onset right kidney stone with evidence of gall stones on CT scanning. He has a long history of episodic hemoglobinuria, hemosiderinuria and LDH elevation. He also has a history of iron deficiency anemia, and prior DVT of the left arm. He had a bowel resection two months ago related to a “blood clot” of the small intestine…
What is the cause of the hemoglobinuria?
Why has the patient had venous and arterial blood clots?
What will flow cytometry reveal?
He has hemosiderinuria b/c of intravascular hemolysis
LDH elevation b/c of hemolysis
Iron deficiency anemia (hemoglobinuria)
Arterial and venous thrombosis (complement actived thrombosis)
He has paroxsymal nocturnal hemoglobinuria- where complement is attacking his RBCs
you can end up with malabsorption
Flow cytometry reveals deficiency of CD 59 and CD 55 (due to lack of glycosylphoshatidylinositol (GPI) anchor for complement – regulating proteins)
with short bowel syndrome, what type of diarrhea will occur?
what is the effect on bile salts and B12 with terminal ileal resection?
you get fatty chronic diarreah- steathorrea
malabsorption type- short bowel syndrome
with terminal ileal resection you get malabsorption of bile salts and B12
without bile salts, he can’t solubilize cholesterol so you get cholesterol gallstones
unabsorbed FA’s bind calcium, decreased absorption of calcium occurs along with increased absorption of oxalate so oxalate kidney stones form
what type of diarrhea do you get with irritable bowel disease?
inflammatory diarrhea
due to Increased fecal serine protease activity, probably from an altered fecal flora!” You have 3 pounds of bacteria in your gut with 30,000 species and multiplying!
when diarrhea is post-prandial (after eating) consider what?
Celiac and Crohn’s
then proceed to Sudan III and fecal elastase-1.
If the latter is below (or even above) 100 ug/g stool, then try pancreolipase.
A bile acid binder should also be tried and even an alpha glucosidase might be worth a try. If this fails give a trial of an antibiotic for bacterial overgrowth and as a last resort consider an endocrine tumor. When all these options are exhausted, rest you laurels on IBS.
skin biopsy shows granular deposits of IgA in the tips of the dermal papillae (on extensor surfaces)
rash is dermatitis herpetiformis
celiac disease
what type of diarrhea do you get with celiac
malabsorption fatty diarrhea
Extraintestional manifestations: elevated liver and pancreatic
enzymes; infertility or spontaneous miscarriages; iron deficiency
anemia; peripheral neuropathy; diabetes type 1, Addisons,
osteopenia
Celiacs
do a mucosal biopsy villous atrophy and crypt hypertrophy with lymphocyte and plasma cell infiltration.
what if a pt has celiacs and they start to develop overactive diarrhea despite being gluten free?
suspect they developed a B cell lymphoma
HLA-DQ2(MHC class II molecules) present antigen peptides to CD4 (TH0) cells resulting in production of IgA against EMA and tTG (tissue transglutaminase)
TH2 cells activate b cells –> overactivation can lead to lymphoma
a stool pH of <5 indicates what?
presence of FFAs consisting of butyrates, acetates, and proprionates which are all organic anions produced when colonic bacteria carry out fermentation on fecal CHOs. Thus, a stool pH of 3.5 would point to excess CHOs (carbohydrates) and an osmotic diarrhea.
what are the causes of nonerosive atrophic gastritis
pernicious anemia
h. pylori
why would a pt with pernicious anemia get bacterial overgrowth and get two different kinds of diarrhea?
with pernicious anemia you have loss of parietal cells so loss of acid–> no acid is getting to the small intestine so you get bacterial overgrowth
the patient has watery diarrhea b/c of the osmotic load of unabsorbed CHO’s
( proteases from the bugs destroy the brush border disaccharidases) arriving in the colon. The colonic bacteria carry out fermentation on these CHOs with the additional production of FFAs consisting of butyrates, acetates, and proprionates which are all organic anions that lower the pH of the stool content to less than pH 5. The bacteria also consume B12 and other nutrients.
In addition, the bacteria deconjugate bile acids. This results in malabsorption of fat with resultant steatorrhea* from lack of micelle formation, and the subsequent parade of these deconjugated bile acids to the colon where they further irritate and produce a secretory diarrhea, in this case accounting for the increased stool volume.
how do you prove that the problem of diarrhea is bacterial overgrowth
d-(14C)xylose breath test - when you take this in, the gut bacteria metabolize to CO2
CO2 is measured in the expired air at 30 minutes
Hydrogen breath test: Give 50 gm of lactose and measure
breath hydrogen. In 90 minutes will have > 20 ppm of hydrogen from bacterial metabolism in the colon. An earlier peak (30 minutes) will be seen in bacterial overgrowth.
fever of undetermined origin
3 weeks duration
Temp over 38.3 (101) on several occasions
No diagnosis after 3 office visits or 3 days of hospitalization or one week of evaluation.
multisystem involvement
fever, lymphadenopathy, arthralgias, weight loss, malabsorption , chronic diarrhea
PAS positive macrophages
heart murmurs
positive stool leukocytes
whipple disease
causes edema b/c of loss of protein
malabsorption type fatty diarrhea
