Diarrhea Path

Question 1

Acute vs chronic diarrhea

Answer 1

Acute 4 weeks in duration

Question 2

What is stool osmotic gap? What is it used for?

Answer 2

Stool osmotic gap= 290-2x (stool Na+ stool K)

Used to distinguish between secretory (gap125)

Question 3

What is secretory diarrhea?

Answer 3

Results from decreased absorption or increased secretion in small bowel.

No significant stool osmotic gap. Does not abate with fasting

Question 4

What is osmotic diarrhea?

Answer 4

Presence of osmotically active, poorly absorbed solutes in bowel lumen that inhibit normal water and electrolyte absorption

Elevated osmotic gap; abates with fasting

Question 5

Describe malabsorbitive diarrhea

Answer 5

Failure of nutrient absorption associated with steatorrhea. Relieved by fasting

Caused by numerous pathologic conditions (pancreatic insufficiency, biliary disease, Crohn’s, celiac)

Question 6

Describe exudative diarrhea

Answer 6

Prurulent bloody stools due to inflammatory disease. Inflammatory products and altered absorption of fluid/electrolytes

Continues during fasting

Question 7

What are causes of acute diarrhea?

Answer 7

90%=infectious agents (norovirus most common, but also campylobacter, salmonella, shigella, E Coli
10%=meds, toxic ingestions, ischemia, food indiscretions,

Question 8

What is pseudomembranous colitis?

Answer 8

C difficile overgrowth results in toxin release that cases ribosylation of GTPases and disruption of epithelial cytoskeleton, tight junction barrier loss, cytokine release and apoptosis

Question 9

Describe Gross and histol appearance of pseudomembranous colitis

Answer 9

DO it

Question 10

What are types of ischemic colitis?

Answer 10

Mucosal infarction and mural infarction secondary to chronic hypoperfusion or transmural infarction secondary to acute vascular obstruction

Question 11

What are two phases of intestinal ischemia?

Answer 11

Hypoxic injury then reperfusion injury