MIDTERM - FECAL ANALYSIS Flashcards
In the minds of most laboratory personnel, fecal specimen analysis
fits into the category of a “___.”
necessary evil
Routine fecal examination includes ___
macroscopic,
microscopic, and chemical analyses
the fecal routine analysis such as macroscopic, microscopic, and chemical analysis, it will provide an early detection for what diseases and conditions?
gastrointestinal bleeding, liver and biliary duct disorders, maldigestion and malabsorption disorders, pancreatic diseases, inflammation, and causes of diarrhea and steatorrhea
`The normal fecal specimen contains _
bacteria, cellulose, undigested foodstuffs, GI secretions, bile pigments, cells from the intestinal walls, electrolytes, and water
. Approximately ___ g of feces
is excreted in a 24-hour period
100 to 200
___ produces
the strong odor associated with feces and intestinal gas (flatus)
Bacterial metabolism
It is the waste residue of indigestible materials of an
animal’s digestive tract expelled through the anus during
defecation
feces or stool
Lactose intolerance leads to __
excessive gas production
Produces strong odor and flatus
bacterial metabolism
_____, especially oligosaccharides, that are resistant to digestion pass through the upper intestine unchanged but are metabolized by bacteria in the lower intestine, producing large
amounts of flatus
Carbohydrates
Excessive gas production also occurs in ___ people when the intestinal bacteria metabolize the
lactose from consumed milk or lactose-containing substances.
lactose-intolerant
Although digestion of ingested proteins, carbohydrates, and fats takes place throughout the alimentary tract, the ____ is the primary site for the final breakdown and reabsorption of these compounds
small intestine
Digestive enzymes secreted into the
small intestine by the pancreas include ___,___, ____ , and __
trypsin, chymotrypsin,
amino peptidase, and lipase
__ provided by the liver aid
in the digestion of fats
Bile salts
Excess undigested or unreabsorbed materials then appear
in the feces, and the patient exhibits symptoms of __.
maldigestion
and malabsorption
9000 ml of fluid including saliva, gastric, liver, pancreatic secretions enter the digestive tract each day but only ___ ml are excreted
150 ml
how many ml of water from 9000 ml intake reaches the small and large intestine
500 to 1500 ml
up to how many ml of water do colon can reabsorbed?
3000 ml of water
pancreas secreted up to how many ml of secrtions?
1000 ml
intestinal secretions composed of water and electrolytes is about how many ml
2000 ml
bile from liver is about how many ml?
1000 ml
saliva is about how many ml?
1500 ml
how many ml of water do food and intake water contributes in 9000 ml
2000 ml
gastric secretions is about how many ml ?
1500 ml
mucous secretions in the GI tract is about?
200 ml
The large intestine is capable of absorbing approximately ___mL of water
3000
When the amount of water reaching the large intestine exceeds this amount (3000 ml), it is excreted with the solid fecal material, producing ____
diarrhea
____, on the other hand, provides time for additional water to be reabsorbed from the fecal material, producing small,
hard stools.
Constipation
____ is defined as an increase in daily stool weight above 200 g, increased liquidity of stools, and frequency of more than
three times per day.
Diarrhea
Diarrhea classification can be based on four
factors what are they?
illness duration,
mechanism,
severity,
stool characteristics
Diarrhea lasting less than 4 weeks is defined as ___
acute
Diarrhea lasting more than 4 weeks is defined as ___
chronic
The major mechanisms of diarrhea are ___, ___, and ___
secretory, osmotic, and intestinal hypermotility
The major mechanisms of diarrhea are secretory, osmotic, and intestinal hypermotility.
The laboratory tests used to
differentiate these mechanisms are ___
–fecal electrolytes (fecal sodium, fecal potassium),
–fecal osmolality,
–and stool pH
The normal total fecal osmolarity is close to the serum osmolality
_____mOsm/kg
290 mOsm/kg
normal fecal sodium is ___ mmol/L
30 mmol/L
normal fecal potassium is ___ mmol/L.
75 mmol/L
The fecal sodium and fecal potassium
results are used to calculate the ____
fecal osmotic gap.
describe the difference between the osmotic gap and electrolytes of osmotic diarrhea and secretory diarrhea
osmotic diarrhea > 50 mOsm/kg
electrolytes negligible
secretory diarrhea <50 mOsm/kg
electrolytes increased
A fecal fluid pH of less than ___ indicates a malabsorption of sugars, causing
an osmotic diarrhea
5.6
___ diarrhea is caused by increased secretion of water.
Secretory
what are the causes of increase production or secretion of water and electrolytes in secretory diarrhea
Bacterial, viral, and protozoan infections
what is the mechanism of secretory diarrhea
Usually caused by an organism that produces a toxin that
stimulates adenylase cyclase enzyme that leads to crampy
diarrhea & secretion of intestinal fluid
the mechanism of secretory diarrhea Usually caused by an organism that produces a toxin that
stimulates ___ that leads to crampy
diarrhea & secretion of intestinal fluid
adenylase cyclase enzyme
secretory diarrhea stools are characterized as
watery and voluminous with no RBC,
WBC, and mucus
causative agents of secretory diarrhea
o Vibrio Cholerae
o ETEC (Travelers’s bacterial Diarrhea)
o Giardia lamblia
Other causes of secretory diarrhea are
drugs, stimulant laxatives,
hormones, inflammatory bowel disease (Crohn disease, ulcerative colitis, lymphocytic colitis, diverticulitis), endocrine disorders (hyperthyroidism, Zollinger-Ellison syndrome, VIPoma),
neoplasms, and collagen vascular disease.
increase production of water caused by bacterial, viral, and protozoan infections, will override the __ of large intestine resulting to secretory diarrhea
reabsorptive ability of the large intestine,
Process specimens for osmolality testing
immediately. Specimens that are stored for hours may
have a markedly increased osmolality due to the increased
degradation of carbohydrates.
true or false
true
is caused by poor absorption that exerts osmotic pressure across the intestinal mucosa.
osmotic diarrhea
Incomplete break
down or reabsorption of food presents increased fecal material to
the large intestine, resulting in water and electrolyte retention in
the large intestine
osmotic diarrhea
what is the mechanism of osmotic diarrhea
Usually caused by inefficient reabsorption of an osmotic substance due to an enzyme deficiency
___(impaired food digestion) and
___(impaired nutrient absorption by the intestine) contribute to osmotic diarrhea
Maldigestion ; malabsorption
explain the relationship of the osmolality and the concentration of the electrolyte in terms of the unabsorbable solutes
increases the stool osmolality
concentration of electrolytes is lower
resulting in an increased osmotic gap
osmotic diarrhea stools are characterized by
Stool samples are watery and Gaseous with no WBC, RBC, and
mucus
causes of osmotic diarrhea based on the ppt
o Lactose intolerance
o Pancreatic insufficiency
Differential features for Diarrhea
osmotic diarrhea has _____ in terms of osmotic gap
> 50 Osm/kh
Differential features for Diarrhea
osmotic diarrhea has ____ in terms of stool Na
<60 mmol/L
Differential features for Diarrhea
osmotic diarrhea has __ in terms of stool output
<200 g
Differential features for Diarrhea
osmotic diarrhea has ___ in terms of pH
<5.3
Differential features for Diarrhea
osmotic diarrhea is ___ in terms of reducing substance
positive
Differential features for Diarrhea
secretory diarrhea has __ in terms of osmotic gap
<50 Osm/Kg
Differential features for Diarrhea
secretory diarrhea has __ in terms of stool Na
> 90 mmol/L
Differential features for Diarrhea
secretory diarrhea has ____ in terms of stool output in 24 hr
> 200 g
Differential features for Diarrhea
secretory diarrhea is ___ in terms of reducing substance
negative
Causes of osmotic diarrhea include ___
disaccharidase deficiency (lactose intolerance),
malabsorption (celiac sprue),
poorly absorbed sugars (lactose, sorbitol, mannitol), laxatives, magnesium-containing
antacids, amebiasis, and antibiotic administration
what are the 4 common test for secretory diarrhea
Stool cultures
Ova and parasite
examinations
Rotavirus immunoassay
Fecal leukocytes
osmotic diarrhea common fecal test
Microscopic fecal fats
Muscle fiber detection
Qualitative fecal fats
Trypsin screening
Microscopic fecal fats
Muscle fiber detection
Quantitative fecal fats
Clinitest
D-xylose tolerance test
Lactose tolerance test
Fecal electrolytes
Stool pH
Fecal osmolality
higher pH will cause __ (osmotic or secretory?)
secretory
presence of reducing substance in secretory
negative
___ describes conditions of enhanced motility (hypermotility) or slow motility (constipation)
Altered motility
hypermotility and slow motility are both can be seen in ___
irritable bowel syndrome
a functional disorder in
which the nerves and muscles of the bowel are extra sensitive,
causing cramping, bloating, flatus, diarrhea, and constipation
irritable bowel syndrome
IBS can be triggered by___
food, chemicals, emotional stress, and
exercise.
is the excessive movement of in
testinal contents through the GI tract that can cause diarrhea
because normal absorption of intestinal contents and nutrients
cannot occur.
intestinal hypermotility
___ describes hypermotility of the stomach and the shortened gastric emptying
half-time, which causes the small intestine to fill too quickly
with undigested food from the stomach
Rapid gastric emptying (RGE) dumping syndrome
Healthy people have a gastric emptying half-time range of ___minutes
35 to 100
A gastric emptying time of less than
35 minutes is considered ___
RGE or rapid gastric emptying dumping syndrome
Normal gastric emptying is controlled by ___
fundic tone, duodenal feedback,
and GI hormones
RGE can be divided into early dumping and late dumping
depending upon how soon after a meal the symptoms occur.
___symptoms begin 10 to 30 minutes following meal ingestion.
early dumping syndrome
a classification of late RGE which occurs ___after a meal and is characterized by weakness, sweating, and dizziness
2 to 3 hrs
___ is often a complication of
dumping syndrome
Hypoglycemia
The main causes of dumping syndrome
include ___.
gastrectomy, gastric bypass surgery, post vagotomy status, Zollinger-Ellison syndrome, duodenal ulcer disease, and
diabetes mellitus
Detection of ___ is useful in diagnosing pancreatic insufficiency and small-bowel disorders that cause malabsorption
steatorrhea (fecal fat)
it is the Absence of bile salts that assist pancreatic lipase in the breakdown and subsequent reabsorption of dietary fat (primarily triglycerides) produces an increase in stool fat that exceeds 6 g per day.
steatorrhea
steatorrhea has an increase of stool fat amounting __ g more per day
exceeds 6g per day
pancreatic disorders, including
- cystic fibrosis,
-chronic pancreatitis, and
- carcinoma,
that DECREASE THE PRODUCTION OF PANCREATIC ENZYME, are the conditions associated with steatorrhea
true or false
true
Steatorrhea may be present in both
maldigestion and malabsorption conditions and can be distinguished by the what test?
D-xylose test
___ is a sugar that does not
need to be digested but does need to be absorbed to be present
in the urine.
D-Xylose
If urine D-xylose is low, the resulting steatorrhea indicates a ___
malabsorption condition
A normal D-xylose test indicates __
pancreatitis
Faeces / feces is the plural of latin term “faex”
meaning ___.
residue
__ is the newborn’s first feces.
Meconium
___ or ___ is the study of feces.
Scatology or Coprology
Usually caused by an organism that produces a toxin that stimulates adenylate cyclase enzyme
that leads to crampy diarrhea & secretion of
intestinal fluid
Secretory Diarrhea
secretory diarrhea stools are characterized as watery and voluminous with no rbc, wbc & mucus
true or false
true
Causative agent of secretory diarrhea
○ Vibrio cholerae
○ ETEC (traveler’s bacterial diarrhea)
○ Giardia lamblia
Invasive Diarrhea is mostly caused by
bacteria
Invasive organisms destroys the mucosal lining of the intestines producing pus, blood and mucus in stool.
invasive diarrhea
Stool may contain wbc, rbc, & specks of mucus; and sometimes the organism.
invasive diarrhea
Patient is experiencing tenesmus.
invasive diarrhea
a frequent urge to go to the bathroom without
being able to defecate
tenesmus
invasive diarrhea is caused by
○ Shigella dysenteriae
○ Entamoeba histolytica
○ ETEC
○ Campylobacter jejuni
○ Yersinia enterolitica
Usually caused by inefficient reabsorption of an
osmotic substance due to an enzyme deficiency
osmotic diarrhea
Stool samples are watery & gaseous with NO wbc, rbc & mucus
osmotic diarrhea
Technologist must be aware of contaminants such as
o Urine
o Water
o Paper
MACROSCOPIC EXAMINATION of fecal
color
consistency
form
Normal color is
brownn
the one responsible for the color of the stool
Urobilinogen is converted to urobilin and
stercobilin
Pale color signifies ___ (acholic stool)
biliary obstruction
Bleeding can turn the stool into what colors
red and black
upper git infection causes the stool to turn
black
lower git infection causes the stool to turn
red (hematochezia)
Black/Tarry colored stool causes
- UGIT
- Iron therapy
- Charcoal
Intake - Bismuth
intake
red colored stool causes
- LGIT
- Beets intake
- Rifampin
intake
Pale Yellow,
White, Gray colored stool causes
- Bile duct
obstruction - Barium
intake
how many days it takes for the blood to appear in the stool if it came from esophagus, stomach, or duodenum
takes approx 3 days
that is why UGIT blood has colored black or tarry stool and not red, the blood was unable to retain its original color (red) due to long time of being inside the GIT
green colored stool causes
biliverdin/oral antibiotics
green vegetables
bulky/frothy stool appearance is caused by
bile duct obstruction
pancreatic disorders
ribbon like appearance of stool; is caused by
intestinal constriction
mucus or blood streak stool is caused by
colitis
dysentery
malignancy
constipation
macroscopic examination: consistency
what are the things we need to take note in terms of it?
form, hardness, and watery state
normal form of stool
cylindrical
ribbon like form of a stool signifies __
intestinal constriction on the structure such as tumor blockage
small round/scybalous form of a stool signifies __
constipation
bulky and frothy form of a stool signifies __
steatorrhea
( bile duct obstruction and pancreatic disorders)
mucoid form of a stool signifies __
colitis, constipation
possible causes of stool form bulky frothy
bile duct obstruction
pancreatic insufficiency
possible causes of stool form ribbon like
interstitial constriction due to malignancy (color cancer)
possible causes of stool form mucus and blood-streaked stool
-amoebic colitis
-dysentery
- malignancy
describe the type of stool base on the form
type 1-7
separate hard lumps, like nuts (hard to pass)
type 1
describe the type of stool base on the form
type 1-7
sausage-shaped but lumpy
type 2
describe the type of stool base on the form
type 1-7
like a sausage but with cracks on its surface
type 3
describe the type of stool base on the form
type 1-7
like a sausage or snake, smooth and soft
type 4
describe the type of stool base on the form
type 1-7
soft blobs with clear-cut edges (passed easily)
type 5
fluffy pieces with ragged edges, a mushy stool
type 6
describe the type of stool base on the form
type 1-7
watery, no solid pieces, entirely liquid
type 7
__- and ___ are the substances that produce normal
odor formed by intestinal bacterial fermentation and
putrefaction.
indole and skatole
A foul odor is caused by the degradation of ____
undigested protein and excessive carbohydrate intake.
A sickly sweet odor is produced by ___
undigested lactose.
a chemical test that is done for Hidden blood, not seen by microscopic examination
Fecal Occult Blood
a blood that is Normally found in small amount,___ of
stool.
2.5ml/ 150 grams
Screening test for colorectal cancer & git bleeding
Fecal occult blood
what is the principle of the fecal occult blood
Based on the pseudoperoxidase activity of
hemoglobin molecule reacting with the
chromogen
is commonly used because it is not too
sensitive (avoids high false positive)
gum guaiac
is the most sensitive chromogen
benzidine
the positive result for O-toluidine
blue chromogen
Pale stools are also associated with
diagnostic procedures that use ___
barium sulfate.
False-positive reaction for fobt
- NSAIDS
- Contamination of menstrual
blood - Hemorrhoids
- Non adherence to diet advice
false negative for fobt reaction
vitamin c and iron intake
Substances that may also exhibit pseudoperoxidase
activity/ reaction:
○ Hemoglobin
○ Myoglobin
○ Vegetables
○ Fruits
Dietary restrictions 3 days before the examination
○ Red meat
○ Horseradish
○ Melons
○ Raw broccoli
○ Turnip
○ Vitamin C and iron
___ specific for globin portion of
human hemoglobin. uses anti-human hemoglobin
antibodies.
Hemoccult ICT (IFOBT)
Immunochemical Fecal Occult Blood
It does not require dietary or drug restrictions.
Immunochemical Fecal Occult Blood
It is more sensitive to lower gi bleeding that could be
an indicator of colon cancer or other gi disease and
can be used for patients who are taking aspirin and
other anti-inflammatory medications.
Immunochemical Fecal Occult Blood
offers a porphyrin-based fobt
fluorometric test for hemoglobin based on the
conversion of heme to fluorescent porphyrins. the test
Hemoquant
measures both intact hemoglobin and the hemoglobin
that has been converted to porphyrins.
Hemoquant
(Porphyrin-based Fecal Occult Blood)
Determines if infant’s stool or vomitus is fetal or
maternal in origin
chemical examination: apt test
principle of apt test
Principle:
○ “Fetal blood resist alkali denaturation (remains pink) while maternal blood is sensitive to alkali denaturation (yellow brown).”
procedure of apt test
Specimen in emulsified with water, centrifuged then added with 1% NAoH.
result of apt test
maternal blood is denature = ___
yellowish brown
result of apt test
fetal flood is unchange
pink
Confirmatory test for Steartorrhea
Quantitative Fecal Fat Testing
Collection of 3 day fecal specimen
Quantitative Fecal Fat Testing
Methods for quantitative fecal fat testing
Van de Kamer Titration (gold standard)
Rapid test for quantitative fecal fat testing
acid steatocrit
MICROSCOPIC EXAMINATION of fecal will check on
● WBCS
● Increased fecal fat
● Meat or muscle fibers
__ are positive for fecal wbc.
Invasive organisms
__ organisms are negative for fecal wbc.
Toxin producing
fecal wbc is assesed using __
Wet preparation with methylene blue, gram’s stain or wright’s stain
3 wbc/ hpf is significant for fecal wbc
true or false
true
test for fecal wbc
Lactoferrin latex agglutination test
Detects fecal wbc even on frozen specimen
Lactoferrin latex agglutination test
clinical significance of wbc in fecal test
▪ Ulcerative Colitis
▪ Dysentery (Bacterial)
▪ Ulcerative diverticulitis
▪ Intestinal TB
▪ Abscess
Signifies pancreatic insufficiency (acute and chronic pancreatitis, cystic fibrosis)
muscle fiber
Usually associated with bulky frothy stool with lots of fecal fat
muscle fiber (Signifies pancreatic insufficiency)
muscle fibers is predominant in patient’s stool with
Gastrocolic fistula (abnormal connection of the
stomach and intestine)
describe the striations of digested meat fibers
no striations
describe the striation of a partially digested meat fibers
fibers has 1 stration
describe the striation of undigested fibers
has 2 striations or more than
Fecal WBCs are seen in __ and ___
bacterial dysentery and ulcerative colitis
Wet preparation for fecal wbc
methylene blue
gram stain
wright stain
how many wbc per hpf is considered significant in fecal wbc test?
3 WBC/HPF is significant
a microscopic screening that is Done in cases steatorrhea and Malabsorption syndromes
qualitative fecal fat
Types of fats:
o Neutral Fat (TAG)
o Fatty Acid; Salts or Soaps
o Fatty acid
o Cholesterol
Stain used in qualitative fecal fat
sudan 3 (Most commonly used),
4 or ORO
