1What is the main use of fecal analysis?
to detect bleeding in GI tract
2What is a common reason for GI bleed?
Medications that are caustic, that inhibit protective layer of mucous membrane that lines stomach.
3What does dark stool indicate?
upper GI bleed
4What does red stool indicate?
lower GI bleed
5How is steatorrhea different from diarrhea?
Steatorrhea has significantly increased fat content
>7g
6What are some things that can increase the fat in stool?
1. Medical treatments (ex. Oristat : weight reduction medication that inhibits breakdown of lipids in gut so fat is not absorbed)
2. Malignancy (ex. pancreatic cancer, pancreas that usually produces all the enzymes to break down food. no pancreas = cant break down fat and remains in stool)
7How much liquid enters intestines each day? How much comes out?
9000 mL liquid enters, 150 mL leaves in the form of 100-200 g feces
8What is the majority of the dry weight (no water) of feces?
bacteria!
9What is the main site of absorption?
The small intestine (responsible for absorption and digestion)
10What is the job of the large intestine?
Absorption of water, Na, Cl, and vitamins
11What is an example of vitamin in the large intestine?
Vitamin K
12What is the importance of vitamin K in newborns?
Vitamin K injection is needed for coagulation (prevention of bleeding) because the gut of a newborn is sterile, and vitamin K production is by gut bacteria
13When does diarrhea develop?
if the water absorption is inhibited or inadequate time is allowed for absorption
14When does constipation occur?
from stationary bowel contents or decreased intestinal motility
15What keeps the intestines attached and in place?
the mesentary
16What are necessary for fat digestion?
bilirubin (color), bile salts (absorption of fats), pancreas juices (other enzymes needed)
17What happens when there is pancreatic cancer?
bile path is obstructed, backs up to liver, backs up to blood, presence of conjugated bilirubin in urine (because the prob is not he liver, but the pathway)
18What is the color of stool in pancreatic cancer?
acholic, white-gray (no bilirubin)
19What are the 3 kinds of diarrhea?
secretory, osmotic, and intestinal hypermotility
20What is secretory diarrhea?
when increased SOLUTE secretions by intestines draws water and electrolytes INTO intestine
21What is osmotic diarrhea?
when increased osmotically active solutes draw water and electrolytes into intestine.
22What is intestinal hypermotility diarrhea?
decreased time avail for absorption (can be alone or with secretory/osmotic)
23What are some things that can cause intestinal hypermotility?
laxatives, stress, drugs, other diarrheas
24What is an example that can cause secretory diarrhea?
Exposure of cholera which produces toxins, affecting enterocytes, preventing normal fxn of protein channels that maintain Cl ions.
Cl ions to intestinal lumen.
Then, Cl attaches to Na (where Na goes Water will go) and remains in intestinal tract, keeping the water in.
25What is an example that can cause osmotic diarrhea?
Lactose intolerance (cant break down lactose due to missing lactase). Lactose (osmotically active) stays in the intestine pulling water from blood to intestines
26What is the mechanism for intestinal hypermotility?
Intestinal hypermotility relies of fxn of smooth muscle to contract/push (peristalsis) too quickly/strongly
27How do you tell the difference between secretory and osmotic diarrhea?
True osmolality - calc fecal osmolality =
>20 mOsm/kg = osmotic
< 20 mOsm/kg = secretory
28What is the formula for calculated fecal osmolalility?
calc fecal osmolalty = 2*(Na of fecal + K of fecal)
29What are 2 examples of secretory diarrhea (from ppt?)
Enterotoxin-producing organisms and damage to mucosa due to drugs/disease
30What are the 2 kinds of osmotic diarrhea?
Maldigestion and Malabsorption
31Which osmotic diarrhea is finding an increase of triglyercides in stool?
Maldigestion because triglyceride should get broken down to fatty acidslycerol. If in urine, it did not get digested.
32Which osmotic diarrhea is finding an increase of fatty acids in stool?
Malabsorption because it WAS digested (from triglycerides) but was not reabsorbed into body
33What are some additional examples of malabsorption?
crones disease, celiac disease, lymphomas
34What is the #1 obvious sign of steatorrhea?
foul foul odor (and greasy)
35What happens when fecal WBCs are present?
inflammation / infection
36Can you rule out infection when fecal WBC?
No because some parasites/viruses do not increase WBC
37After fecal fat is found >7g, what should you check? why?
Check for hepatobiliary disease to make sure necessary things needed to break down lipids is working.
38If you put 10g of xylose in, and only see 1g of xylose coming out, what can you assume?
Maldigestion because most of it is absorbed.
39Why is xylose used?
it's a monosaccharide that doesnt get broken down more
40If you put 10g of xylose and see 9g in stool, what can you assume?
Malabsorption because none (very little) of it went back into the body and went straight out.
41What is the normal color of feces?
brown but can temporarily fluctuate depending on external factors
42What does pale/clay colored feces mean?
Acholic stool, no bilirubin present, therefore and issue before reaching intestine
43What does mucus say about feces?
the GI lining is enflamed, possibly colon cancer
44What are indoles?
Protein breakdown causing a stinky smell. (to get rid of, reduce protein intake)
45If you are gassy, what should you do?
decrease carbohydrate intake
46What does fecal WBC indicate?
inflammation / infection
47What do excessive meat fibers in feces suggest?
suggests problem with protein breakdown (cannot convert to amino acids)
48What is the reachtion in the occult blood test?
guaiac and hydrogen peroxide = blood present (blue)
49What is fecal blood an early symptom for?
colorectal cancer
50What is the definitive test for steatorrhea?
quantitative fecal fat
51How is the quantitative fecal fat done?
using NaOH (strong base) and Acetic Acid to determine neutral lipids (from NaOH test) or fatty acids (from acetic acid test)
52What is a neutral lipid?
triglyceride
53What does undigested carbs in stool result in?
bloating, farts, & explosive diarrhea due to fermentation of normal flora
54What is the pH of stool when carbs are present?
pH 5-6 (slightly acidic) versus the normal pH >7
55What test can detect carbs?
Reducing substances (Clinitest)
56What is the purpose of the Apt test?
Differentiates fetal (internal bleeding)and maternal blood in newborn's stool (swallowing amniotic fluid at time of birth)
57What does the Apt test use?
Hemoglobin
58How is fetal hemoglobin different from adult hemoglobin?
Fetal hemoglobin (Hgb F) is resistant to alkalinization, wont be denatured / broken down by alkaline situation whereask Hgb A is very susceptible to alkaline solutions
59What agent is used in the Apt test?
NaOH (strong base) that degrades maternal but not fetal hemoglobin.
Fetal turns red whereas the adult turns brownish due to breakdown of material
60What is early/pre-cancer of the colon called?
adenoma