2 Disease of lower GI: path - [3] deveraj

Question 1

pathogenesis of Celiac disease (gluten sensitive enteropathy)

Answer 1

Gluten digested by luminel + brush border enzymes →
exposure to α-gliadin peptide results in autoAb formation →
inflammation (↑ T lymph) →
villous atrophy →
tissue damage →
loss of mucosal and brush border surface area →
malabsorption, diarrhea

Question 2

classical presentation of celiacs

Answer 2

bulky fatty diarrhea
flatulence
weight loss
anemia
nutritional deficiencies
growth failure in children

Question 3

3 characteristic findings in tissue biopsy for Celiacs

Endoscopy findings?

Answer 3

1. villous blunting
2. increased intraepithelial lymphocytes
3. lymphoplasmacytosis of the lamina propria

scalloped appearance
(*note: IgA ab to TTG and anti-endomysial ab)

Question 4

celiacs disease is associated with the blistering skin disease _____

Answer 4

dermatitis herpetiformis

Question 5

Pathogenesis of Whipple disease

Answer 5

caused by gram (+) bacilli Tropheryma whippelii
- bacilli absorbed by lamina propria macrophages →
organism-laden mac. accumulate in sm Int lamina propria + mesenteric lymph nodes → lymphatic obstruction →
malabsorptive diarrhea

“foamy macrophages”

Question 6

clinical features of whipple disease

Answer 6

triad of:
diarrhea, weight loss, malabsorption

typically in middle ages or elderly white males

Question 7

Giardia lamblia

• what
• dx
• sx
• tx

Answer 7

protozoan parasite
waterborne + Cl resistant

dx: trophozites or cysts (cute purple smiley guy)
sx: bloating, flatulence, foul smelling fatty diarrhea
tx: metronidazole

Question 8

Infectious enterocolITIS

- bacterial infections

Answer 8

typically create an acute self-limited colitis

pts usually present several weeks after onset of sx, so tisue biopsy rarely shows classic acute infectious findings

• campylobacter
• shigellosis
• salmonellosis
• E. coli

Question 9

Campylobacter spp

• Gram ___
• usually found ____
• Presentation

Answer 9

gram NEGATIVE major cause of diarrhea worldwide
a leading cause of bacterial foodborne illness in US
- found in contaminated meat (poultry), water, and unpasteurized dairy
Prod. WATERY diarrhea +/- blood

Infectious enterocolITIS

Question 10

Salmonella

• Gram ___
• usually found ____
• Presentation
• Characteristic pathology most commonly seen in:

Answer 10

gram NEGATIVE 
food and water
- food poisoning + travelers diarrhea
- typhoid mary
Prod diarrhea @ 2nd week of infxn initially watery then bloody
ileum, colon, appendix, Peyer's patches

Infectious enterocolITIS

Question 11

Enterohemorrhagic E. Coli
pathology
sx
endoscopy
area of colon affected

Answer 11

[O157:H7] “jack in the box”
non invasive, toxin producing, contaminated hamburgers
bloody diarrhea, severe cramps, mild or no fever, renal failure maybe

Question 12

Pseudomembranous colitis

• commonly caused by
• susceptibility factor?
• sx?
• type of diarrhea?

Answer 12

C. diff
colitis often occurs after course of antibiotic therapy
"antibiotic associated colitis"
- 3rd gen cephalosporins
common in hospitalized pts

sx: fever, leukocytosis, abdominal pain, cramps, watery diarrhea

Question 13

which virus is the most common cause of severe childhood diarrhea and diarrheal mortality worldwide?
- path?

Answer 13

rotavirus
- children 6-24 mo vulnerable

infects and destroys mature enterocytes →
villus surface repopulated by immature secretory cells →
loss of absorptive fxn →
net secretion of water and electrolytes →
osmotic diarrhea →
DEHYDRATION

2 vaccines now available

Question 14

Indiv at risk for ischemic colitis

Answer 14

older indiv w/ co-existing cardiac or vascular disease
young pts: long distance runners, women on oral con.
mech. obstruction: hernias, volvulus

• splenic flexure + rectosigmoid area at risk (watershed)

Question 15

presentation of ischemic colitis

Answer 15

acute transmural infarction → severe abdominal pain
tenderness
n/v
bloody diarrhea
PERISTALSIS SOUNDS DISAPPEAR
rigid abdomen
shock/sepsis

Question 16

what makes up the pseudomembrane in PC?

Answer 16

adherent layer of inflammatory cells and mucinous debris at sites of colonic mucosal injury

surface epithelium denuded, mucopurulent exudates

Question 17

Two histological patterns associated with microscopic colitis

Answer 17

1. collagenous colitis
   - thickened subepithelial collagen layer
   - too many lymphocytes in LP
2. lymphocytic colitis
   - increased intraepithelial lymphocyte
   - too many lymphocytes in LP

Question 18

Does crohns or UC present worse distally by rectum and present with pseudopolyps and has thinner walls

Answer 18

UC

Question 19

Primary sclerosing cholangitis (PSC) is heavily associated with ____

Answer 19

UC

Question 20

fecalith pathopneumonic for ______

Answer 20

appendicitis

- inflammatory response