L83 Flashcards
Describe fat metabolism in the SI
Pancreatic enzymes break into FA
FA -> TG -> chylomicrons = absorbed into lymphatics
Short and medium chain FAs passively diffuse into portal circulation
Major enzyme for protein metab
Pepsin
What gets absorbed in the duodenum
Iron
3 things that get absorbed in the jejunum
Folate
Ca
Zn
What is absorbed in the ileum
B12, fat sol vitamins (ADEK), bile salts
What kind of ab pain makes you think SI
Worse after eating
Peri-umbilical
Describe inflam diarrhea
- Volume: small or large
- What’s in it
- Associated symptoms
Small vol - frequent
Blood, WBC, mucous
Tenesmus, pain, fever
Diseases that present w/ inflam diarrhea
Infections, IBD, ischemia (acute)
Describe non-inflam diarrhea
- Volume: small or large
- What’s in it
- Associated symptoms
Large volume: dehydration
Watery
No fever, etc
Diseases that present w/ watery diarrhea
IBS, medications
Equation to calculate stool osms
290 - [2 x (stool Na + )]
Define osmotic diarrhea
Gap > 50
Means that solutes aren’t being absorbed, therefore stay in GI lumen
Ex: lactose intol, artifical sugars
SO diarrhea gets worse after eating, better when you don’t
Define secretory diarrhea
Gap
Describe fatty diarrhea - what are the 2 reasons you might have this?
Floats
Smells BAD
Either due to maldigestion OR malabsorption of fats
How do you test for these in the stool:
- Fat
- Carbs
- Protein
- Bile salts
Fecal fat - just measure
Carbs - change diet (lactose)
Protein - alpha1 anti-trypsin clearance from stool
Bile salts - + bile acid binder, does it get better?
3 ways to visualize the SI
EGD = scope from above
Colonoscopy
Video capsule = to see the middle
- Otherwise radiology to see the middle SI = enterography
What is Celiac disease - what kind of diarrhea
Ab vs gliadin
Disrupts tight jxns
Activates tissue transglutaminase = tTG -> more aggressive changes
Net: lose mucosa vili -> INFLAM diarrhea
Halpotype for Celiac
DQ2/8
If you don’t have this, you don’t have Celiac
Celiac presentation
Bloating + pain + diarrhea
Nutrient def
Anemia
Skin lesion assicated with Celiac
Dermatitis herpetaformis
What does Celiac look like on scope
Scalloping
What does Celiac look like on histo - 3 features
Lose vili
Hyperplasia of crypts
Intraepithelial lymphocytes***
Test for Celiac
Ab tTG = IgA
BUT if this comes back normal, pt might have associated IgA def
Treat eosinophilic enteritis
Remove allergic food if able
Steroids
