Approach to Diarrhea

Question 1

what is considered diarrhea?

Answer 1

defined by volume of stool. >200g/24 hrs

Question 2

4 mechs of diarrhea

Answer 2

osmotic, secretory, inflammatory, dysmotility

Question 3

osmotic diarrhea

Answer 3

ex. lactose intolerance, sorbitol
stops w/ fasting
increase in stool osmotic gap >100

Question 4

how to calculate stool osmotic gap

Answer 4

290 mosms/kg - 2(Na +K)

Question 5

secretory diarrhea

Answer 5

cumulative secretion of water and electrolytes in small intestine exceeds normal absorptive capacity
ex. cholera, laxatives, lubiprostone

Question 6

inflammatory diarrhea

Answer 6

inflammation –> exudation of blood, lymph, mucus
destruction of epithelial cells that control absorption and secretion
ex. IBD
labs: fecal blood and WBCs

Question 7

dysmotility type diarrhea

Answer 7

abnormal intestinal transit time

ex. post surgical diarrhea –> dumping syndrome

Question 8

acute vs. chronic diarrhea

Answer 8

more than or less than 3 wks

- acute = infectious: usually norovirus, except if in hospital (c. diff) or camping (giardia)