kiddy diarrhea Flashcards
def dia
increased stool fluid content above normal
- over 3 loose/lquid stools per day
location of villi
small and large bowel
how much fluid enters colon and how much is absrobed
1.5-2L/day - 90% absrobed
most important ion for flow
Na
main pump and 3 main mech that pull H2o into body
Na/K pump
- SGLT-1 - glucose/Na cotransporter pulls Na and glucose in from lumen
- Na comes in from electro selective Na channels
- Anion co-exchanger (Cl/CO3)
Main secretory channel
CFTR - pushes Cl into lumen and Cl and Na come into enterocyte - pushes NA out
what is net water movement
follows the gradient that has been created
4 mech that affect electrolytre movement
- enteric nervous system
- lamina propria cells
- mucosal epi cells - somatostatin
- blood
what is important molecule that increases absorbtion
aldosterone - increases Na absorbtion via Na/K pump
how do most substances affect gut levels
via secretion
what are 3 main messangers involved in secretons
- cAMP
- cGMP
- Ca/kinase
how do they work (2)
- inhib. Na/CL influx
2. increase Cl efflux
what part of lumen is most absorbtion and secretion
absorb - villi
secrete -crypt
- since there are more villi than crypt, get fluid absorbtion1
2 types of villous problems with absorbtion
- too little time to absorb
2. not enough ville (destructions)
def osmotic diarrhea
too much solute pulls water into gut
- proportional to intake of solute
- stool ion gap high
- not usually too bad
3 things that might cause osmotic
- carbs
2, fat - protein
2 possible cause of them being there and one possible outcome
- lack of disgestion
- lack of absorbtion
- can ferment and cause gas
what are only carbs that can be absorbed without digestion
glucose and fructose
what happens to fats
- emulsified by bile to micelles
- hydrolized to fatty acids
- absorbed via passive diffusion
what happens to chol.
special transport protein
what happens to protein
hydrolyzed by various proteases then taken up as di/tri peptides or AAs
def secretory diarrhea
increase in enterocyte secretion
features of secretory
large volume
- no response to fasting
- colon responses vary
2 mech of sectetory
- increased secondary messangers
2. loosening of the tight junctions
3 cause of diarrhea
motility
main cause of acute diarrhea
infection
- enteric or extraintestinal
def. chronic diarrhea
> 14 days
what is main question to ask
are they still growing?
- if so, probably not bad
7 “zebra” causes
- protein indegestiokn
- fat assimilation
- bile acid disorders
- general malabsorb
- pancreatic insuff.
- immune based
- defects in electrolyte transport
9 common causes (other than infection)
- diet - sorbitol
- meds
- pancreatic insuff. -CF, inflammation
- bile acid disorders - too little or too much
- carbo malabsorbtion
- immune based - celiac, IBD,
- motility disorders - hirschprung, thyrotoxicosis
- neoplastic
- surgical
important questions on Hx
- age of onset
- duration freq
- birth Hx
- diet
- stool
- med and fam Hx
5 exam points
- growth and demeanor
- clubbing
- nasal polyps
- skin integrity
- perianal appearance
3 most common cause in finfants
- formula intolerance
- CF
- immunodef. states
- most common causes in toddlers
- post-infetious enteritis
- diet related
- celiac
3 most common in older
- celiac
- lactose
- IBD
