FECALYSIS Flashcards
1
Q
end product of metabolism
A
Feces
2
Q
Normal stool contains:
A
bacteria, bile pigments, electrolytes,
GIT secretions, cells, water, cellulose and other undigested
foodstuff, digestive enzymes secreted by the pancreas
(trypsin, chymotrypsin, peptidase, lipase, amylase
3
Q
how much feces is excreted in a 24 hr period
A
- 100 to 200 g of feces is excreted in a 24-hour period
4
Q
metabolized by bacteria in the lower intestine, producing large amounts of flatus
A
Carbohydrates
5
Q
resistant to digestion pass through the upper intestine
unchanged
A
Carbohydrates
6
Q
the ___________ is the primary site for the final breakdown and reabsorption of fat
A
small intestine
7
Q
- provided by the liver aid in the digestion of fats.
A
Bile salts
8
Q
when does signs of maldigestion show
A
when excess undigested or unreabsorbed materials then appear in the feces,
9
Q
how many mL of ingested fluid, saliva, gastric, liver, pancreatic,
and intestinal secretions enter the digestive tract each day
A
9000 mL of ingested fluid, saliva, gastric, liver, pancreatic,
and intestinal secretions enter the digestive tract each day
10
Q
A
10
Q
HOW MYCH FLUID REACHES LARGE INTESTINE AND HOW MUCH IS EXCRETED
A
500 - 1500ML OF FLUID REACHES LARGE INTESTINE WHILE 150ML IS EXCRETED
11
Q
WEIGH OF DIARRGEA [ER DAY
A
> 200 g/day
12
Q
WHAT IS THE TIME DURATION OF ACUTE AND CHRONIC DIARRHEA
A
Acute diarrhea – less than 4 weeks
Chronic diarrhea – more than 4 weeks
13
Q
WHAT ARE THE MAJOR MECHANISMS OF DIARRHEA AND TEST USED TO DIFF THEM
A
Major mechanisms
o Secretory
o Osmotic
o Altered motility
- Tests used to differentiate these mechanisms are:
o Fecal electrolytes (fecal sodium, fecal potassium), fecal
osmolality, and stool pH
14
Q
Normal total fecal osmolality close to the serum
osmolality
A
(290 mOsm/kg)
15
Q
o Normal fecal sodium:
A
30 mmol/L
16
Q
o Normal fecal potassium:
A
75 mmol/L
17
Q
he fecal sodium and fecal potassium results are used
to calculate the
A
fecal osmotic gap.
18
Q
OSMOTIC GAP OF OSMOTIC AND SECRETORY DIARRHEA
A
Osmotic diarrhea is >50 mOsm/kg
Secretory diarrhea is <50 mOsm/kg
19
Q
are increased in secretory diarrhea and
negligible in osmotic diarrhea
A
Electrolytes
20
Q
A fecal fluid pH of less than 5.6 indicates a
A
malabsorption of sugars, causing an osmotic diarrhea
21
Q
Stool Na of Osmotic D. and Secretory D
A
> 60 mmol/L = od
<60 mmol/L = sd
22
Q
Stool Output In 24
Hours of Osmotic D. and Secretory D
A
<200g = od
> 200g = sd
23
Q
Ph Osmotic D. and Secretory D
A
<5.3
>5.6
24
Reducing
Substances in sd and od
Positive in od
Negative in sd
25
* Caused by increased secretion of water
Secretory Diarrhea
26
* Stools → watery and voluminous
Secretory Diarrhea
27
↑ secretion of water and electrolytes, which override the reabsorptive ability of the large intestine, leading to______________
* Bacterial, viral, and protozoan infections = ↑ secretion
secretory diarrhea
28
Organisms that stimulate water and electrolyte
secretions:
Enterotoxin-producing organisms, Parasites , INVASIVE DIARRHEA w/ mucus, blood and pus
29
Caused by poor absorption that exerts osmotic
pressure across the intestinal mucosa
Osmotic Diarrhea
30
Increased retention of water & solute in the LI asso.
w/
malabsorption and maldigestion (osmotic d)
31
Incomplete breakdown or reabsorption of food
presents increased fecal material to the large intestine,
resulting in water and electrolyte retention in the large
intestine
OSMOTIC DIARRHEA
32
which in turn results in
excessive watery stool.
OSMOTIC DIARRHEA
33
Stools are watery and gaseous, no wbc, rbc and
mucus (kinakabag and utot ng utot)
Osmotic Diarrhea
34
Presence of unabsorbable solute =
↑stool osmolality
and ↓ concentration of electrolytes, resulting in an ↑
osmotic gap.
35
Specimens that are stored for hours may have a
markedly
increased osmolality due to the increased degradation of
carbohydrates.
36
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)
37
Excessive movement of intestinal contents through the
GI tract that can cause diarrhea because normal
absorption of intestinal contents and nutrients cannot
occur
Intestinal hypermotility
38
Caused by enteritis, the use of parasympathetic drugs,
or with complications of malabsorption
* Intestinal hypermotility
39
t is the hallmark of early dumping syndrome
(EDS)
Intestinal hypermotility
40
Gastric emptying time <35 mins
IS SEEN IN
* Intestinal hypermotility
41
Normal gastric emptying half-time range -
35 to
100 minutes; varies with age and gender
42
Normal gastric emptying is controlled by
fundic
tone, duodenal feedback, and GI hormones
43
WHEN DOES EDS TAKE PLACEW
begin 10 to 30 minutes
44
LATE DUMPINF WHEN FOES IT OCCU
Late dumping - occurs 2 to 3 hours after a meal
45
Dumping syndromes →
Hypoglycemia
46
DIagnoses pancreatic insufficiency and small-bowel
disorders that cause malabsorption
Steatorrhea
47
produces an increase in stool fat
that exceeds 6 g per day
Steatorrhea
48
ncludes pancreatic disorders, including cystic fibrosis,
chronic pancreatitis, and carcinoma, that decrease the
production of pancreatic enzyme
Steatorrhea
49
is a sugar that does not need to be digested but
does need to be absorbed to be present in the urine
D-Xylose
50
f urine D-xylose is low, the resulting steatorrhea indicates
a _______ condition
malabsorption
51
* A normal D-xylose test indicates .
pancreatitis
52
Quantitative collection: Most representative is a 3_______ (specifically for Fecal fat quantification)
Quantitative collection: Most representative is a 3-day
collection (specifically for Fecal fat quantification)
53
Brown color of stool → in
testinal oxidation of stercobilinogen to
urobilin
54
may signify a blockage of the
bile duct;
pale stools (acholic stools)
55
associated with diagnostic procedures that use
barium sulfate.
pale stools (acholic stools)
56
Blood that originates from the esophagus, stomach, or
duodenum
* Black, tarry (melena) stool
57
when does melena stool appear
o Takes approximately 3 days to appear in the stool
58
o Blood from the lower GI tract
Red (hematochezia) stool
59
May be observed in patients taking oral antibiotics,
because of the oxidation of fecal bilirubin to biliverdin
* Green stool
60
ingestion of iron, charcoal, or
bismuth often produces a
black stool,
61
* Small, hard stools →
constipation
62
→ obstruction of the normal
passage of material through the intestine
Slender, ribbon-like stools
63
Pale →
biliary obstruction and steatorrhea;
appear bulky
and frothy and frequently have a foul odor;
may appear
greasy and may float.
64
Mucus-coated stools indicates
intestinal inflammation or
irritation;
caused by pathologic colitis, Crohn disease,
colon tumors,
excessive straining during elimination
65
Macroscopic Stool Characteristics
basahin
66
bristol stool chart
Separate, hard lumps
TYPE 1 - SEVERE CONSTIPATION
67
Lumpy and sausage like
TYPE 2 - MILD CONSTIPATION
68
A sausage-shape with cracks in the surface
TYPE 3 - NORMAL
69
Like a smooth, soft sausage or snake
TYPE 4 - NORMAL
70
Soft blobs with clear-cut edges
TYPE 5 - LACKING FIBER
71
Mushy consistency with ragged edges
TYPE 6 - MILD DIARRHEA
72
Liquid consistency with no solid pieces
TYPE 7 - SEVERE DIARRHEA
73
Mucus- or
blood-streaked
mucus in stool may be due to
* Colitis
* Dysentery
* Malignancy
* Constipation
74
Intestinal constriction
Ribbon-like *
75
Bulky/frothy stool
* Bile-duct obstruction
* Pancreatic disorders
76
Pale yellow,
white, gray stool
* Bile-duct obstruction
* Barium sulfate
77
Red stool
* Rifampin
* Beets and food coloring
* Lower GI bleeding
78
Black stool
* Bismuth (antacids)
* Iron therapy
* Charcoal
* Upper GI bleeding
79
eukocytes, primarily neutrophils in stool
ulcerative colitis and
bacterial dysentery
80
when it is present, Microscopic screening is performed as a preliminary test
to determine whether diarrhea is being caused by invasive
bacterial pathogens
fecal leukocytes
81
Bacteria that cause diarrhea by toxin production, usually do not cause the appearance of fecal
leukocytes
such as
Staphylococcus aureus and Vibrio spp., viruses, and
parasites
82
how many neutrophil per hpf shuold be seen for it to be considered an invasive condition
hree neutrophils per high-power field can be
indicative of an invasive condition
83
is available for
detecting fecal leukocytes and remains sensitive in
refrigerated and frozen specimens
lactoferrin latex agglutination test
84
, a component of granulocyte
secondary granules, indicates an invasive bacterial
pathogen
lactoferrin
85
helpful in diagnosing and
monitoring patients with pancreatic insufficiency (cystic
fibrosis)
Muscle Fibers
86
Frequently ordered in conjunction with microscopic
examinations for fecal fats
Muscle Fibers
87
have visible striations running both
vertically and horizontally
Undigested fibers
88
exhibit striations in only one
direction
Partially digested fibers
89
have no visible striations
Digested fibers
90
when is muscle fiber reported
Only undigested fibers are counted, and the presence of
more than 10 is reported as increased
91
To produce a representative sample, patients should be
instructed to include red meat in their diet before collecting
the specimen
muscle fiber
92
Specimens from suspected cases of steatorrhea can be
screened microscopically for the presence of excess fecal
fat (steatorrhea).
Qualitative Fecal Fats
Qualitative Fecal Fats
93
used to monitor patients undergoing treatment for
malabsorption disorders
Qualitative Fecal Fats
94
Lipids included in the microscopic examination of feces are
neutral fats (triglycerides), fatty acid salts (soaps), fatty
acids, and cholesterol
95
→ Sudan III and appear as large orange-red
* Neutral fats
96
Observation of more than 60 droplets/high-power field
can indicate steatorrhea
neutral fat
97
representing total
fat content
Split fat stain
98
do not stain directly with Sudan III,
so a second slide must be examined after the specimen
has been mixed with acetic acid and heated
Soaps and fatty acids
99
size of droplet of faty and number for it be reported
* Normal specimens may contain as many as 100 small
droplets, less than 4 μm in diameter, per high-power field
* The same number of droplets measuring 1 to 8 μm is
considered slightly increased
* 100 droplets measuring 6 to 75 μm is increased and
commonly seen in steatorrhea
100
is indicated by
increased neutral fat on the first slide
maldigestion
101
is stained by Sudan III after heating and as the
specimen cools forms crystals that can be identified
microscopically
Cholesterol
102
Any bleeding in excess of 2.5 mL/150 g of stool is
considered pathologically significant
Occult Blood
103
* value for detecting colorectal cancer in the early
Occult Blood
104
* The most frequently used screening test for fecal blood
GuaIac-Based Fecal Occult Blood Tests (gFOBT)
105
Based on detecting the pseudoperoxidase activity of
hemoglobin
GuaIac-Based Fecal Occult Blood Tests (gFOBT)
106
Same principle as the reagent strip test for urinary blood,
but uses a different indicator chromogen
GuaIac-Based Fecal Occult Blood Tests (gFOBT)
107
normal stool can contain up to __________
mL of blood
2.5ml
108
facilitated colorectal
cancer screening by allowing patients at home to place
a specimen on a filter paper slide and bring or mail it to
the laboratory for testing
guaiac-impregnated filter paper
109
until when can you test GuaIac-Based Fecal Occult Blood Tests (gFOBT)
within 6 days of
collection
110
Two samples from three different stools should be
tested before a negative result is confirmed
gfobt
111
in gfobt, __________________should
not be taken for 7 days before specimen collection to
prevent possible GI irritation
Aspirin and NSAIDs other than acetaminophen should
not be taken for 7 days before specimen collection to
prevent possible GI irritation
112
______________should be avoided for 3 days before collections,
Vitamin C and iron supplements containing vitamin
C should be avoided for 3 days before collections,
113
Specific for the globin portion of human hemoglobin and
uses polyclonal anti-human hemoglobin antibodies
Immunochemical Fecal Occult Blood Test (iFOBT)
114
specific for human blood in feces, it does not require dietary or drug restrictions
Immunochemical Fecal Occult Blood Test (iFOBT)
115
Hemoglobin from upper GI bleeding is degraded by
bacterial and digestive enzymes before reaching the large
intestine and is _______________
Hemoglobin from upper GI bleeding is degraded by
bacterial and digestive enzymes before reaching the large
intestine and is immunochemically nonreactive
116
There is little hemoglobin degradation in lower GI bleeding,
so the blood is
immunochemically active
117
offers a porphyrin-based FOBT fluorometric test for
hemoglobin based on the conversion of heme to fluorescent
porphyrins
HemoQuant (SmithKline Diagnostics, Sunnyvale, CA)
118
Measures both intact hemoglobin and the hemoglobin that
has been converted to porphyrins
Porphyrin-Based Fecal Occult Blood Test
119
is not affected by the presence of
reducing or oxidizing substances or the water content of the
fecal specimen
Porphyrin-based test
120
False-positive results can occur with the porphyrin-based
test when
non-human sources of blood (red meat) are
present; therefore, patients should be instructed to avoid
red meat for 3 days before the test
121
non-human sources of blood (red meat) are
present; therefore, patients should be instructed to avoid
red meat for 3 days before the test
Quantitative Fecal Fat Testing
122
The patient must maintain a regulated intake of fat (100 g/d)
before and during the collection period
Quantitative Fecal Fat Testing
123
Routinely used for fecal fat measurement is the
van de
Kamer titration,
124
- fecal lipids are converted to fatty acids
and titrated to a neutral endpoint with sodium hydroxide
Titration method -
125
Approximately 80% of the total fat content is measured by
______, whereas the gravimetric method measures ____
Approximately 80% of the total fat content is measured by
titration, whereas the gravimetric method measures all
fecal fat
126
A rapid (5 minutes) and safe procedure for analyzing
quantitative fecal fat is the
hydrogen nuclear magnetic
resonance spectroscopy (1H NMR) method
127
the fat content is reported as
grams of fat or the
coefficient of fat retention per 24 hours
128
Reference values o ffat content based on
Reference values based on a 100 g/d intake are 1 to 6 g/d
or a coefficient of fat retention of at least 95%
129
is the gold standard
for fecal fat, t
Van de Kamer titration
130
is a rapid test to estimate
the amount of fat excretion
acid steatocrit
131
` is a rapid
procedure for fecal fat that requires less stool handling by
laboratory personnEL
Near-infrared reflectance spectroscopy (NIRS)
132
he result is based on the measurement and computed
processing of signal data from reflectance of fecal
surface,
Near-infrared reflectance spectroscopy (NIRS)
133
The technique quantitates water, fat, and nitrogen in
grams per 24 hours.
Near-infrared reflectance spectroscopy (NIRS)
134
are sometimes seen
in neonates as the result of swallowing maternal blood
during delivery.
Grossly bloody stools and vomitus
135
distinguish between the presence
of fetal blood or maternal blood in an infant’s stool or
vomitus,
APT Test (Fetal Hemoglobin)
136
RESULT OF APT TES
In the presence of alkali-resistant fetal hemoglobin, the
solution remains pink (HbF), whereas denaturation of the
maternal hemoglobin (HbA) produces a yellow-brown
supernatant after standing for 2 minutes
137
Distinguishes not only between HbA and HbF but also
between maternal hemoglobins AS, CS, and SS and HbF
APT
138
The presence of maternal thalassemia major would
produce erroneous results owing to the high
concentration of
HbF
139
ssential for digesting dietary proteins,
carbohydrates, and fats
Fecal Enzymes
140
is more resistant to intestinal
degradation and is a more sensitive indicator of less severe
cases of pancreatic insufficiency
Fecal chymotrypsin
141
Remains stable in fecal specimens for up to 10 days at
room temperature
Fecal chymotrypsi
142
Capable of gelatin hydrolysis but is most frequently
measured by spectrophotometric methods
Fecal chymotrypsi
142
Present in high concentrations in pancreatic secretions
and is strongly resistant to degradation
Elastase I
143
Capable of gelatin hydrolysis but is most frequently
measured by spectrophotometric methods
chymotrypsin
144
is an insensitive procedure that detects only
severe cases of pancreatic insufficiency
gelatin test
144
test uses monoclonal antibodies against human
pancreatic elastase-1; therefore, the result is specific for
human enzyme and not affected by pancreatic enzyme
replacement therap
ELISA
145
Screening Test for Fecal Trypsin
False-negative results may occur
as the result of intestinal
degradation of trypsin and the possible presence of
trypsin inhibitors in the feces.
146
Screened for by exposing x-ray paper to stool emulsified in
water
Screening Test for Fecal Trypsin
147
is an insensitive procedure that detects only
severe cases of pancreatic insufficiency
gelatin test
148
screening Test for Fecal Trypsin
False-negative results may occur
as the result of intestinal
degradation of trypsin and the possible presence of
trypsin inhibitors in the feces
149
proteolytic activity of bacteria enzymes may
produce
false-positive
150
Produces osmotic diarrhea from the osmotic pressure of the
unabsorbed sugar in the intestine drawing in fluid and
electrolytes
Carbohydrates
151
May be present as a result of intestinal inability to reabsorb
carbohydrates, as is seen in celiac disease, or lack of
digestive enzymes such as lactase resulting in lactose
intolerance
Carbohydrates
152
Increased concentration of carbohydrate can be
detected by performing a _____________ test on the
fecal specimen
copper reduction
153
detects
congenital disaccharidase deficiencies as well as
enzyme deficiencies due to nonspecific mucosal injury
Testing for fecal reducing substances
154
is most valuable in
assessing cases of infant diarrhea and may be
accompanied by a pH determinationF
Fecal carbohydrate testing
155
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