Fecalysis Flashcards
1
Q
Normal components of a urine
A
Bacteria, Cellulose, Undigested food, Gi secretions, Bile secretions, Cells from intestinal wall, Electrolytes and Water
2
Q
How much feces is excreted within 24 hours?
A
100-200g
3
Q
Responsible for the strong odor associated with feces and flatus?
A
Bacterial metabolism
4
Q
The primary site for the final breakdown and reabsorption of carbohydrates, proteins and fats.
A
Small Intestine
5
Q
What are the digestive enzymes secreted in the small intestine?
A
Trypsin, Chymotrypsin, Amino Peptidase, Lipase
6
Q
What will happen if there are too excessive undigested and unreabsorbed food?
A
Malabsorption and Maldigestion
7
Q
How much ingested fluid, saliva, gastric liver, pancreastic,intestinal secretion enter the digestive tract each day? Under normal conditions, how much of these fluid reach the large intestine? And how much is secreted in the feces?
A
9000 mL; 500-1500 mL; 150 mL
8
Q
The large intestine is capable of absorbing approximately ___________ of water.
A
3000 mL
9
Q
Defined as an increase in daily stool weight above 200 g, increased liquidity of stools, and frequency of more than three times per day.
A
Diarrhea
10
Q
The four factors in which Diarrhea classification is based.
A
Illness duration
Mechanism
Severity
Stool characteristics
11
Q
Diarrhea lasting less than 4 weeks.
A
Acute Diarrhea
12
Q
Diarrhea lasting more than 4 weeks.
A
Chronic Diarrhea
13
Q
What are the major mechanism of Diarrhea?
A
Secretory
Osmotic
Intestinal Hypermotility
14
Q
What are the laboratory tests used to differentiate the mechanisms of diarrhea?
A
Fecal Electrolytes (fecal sodium and fecal potassium)
Fecal Osmolality
Stool pH
15
Q
What is the normal fecal osmolarity?
A
290 mOsm/kg
16
Q
Normal fecal Sodium
A
30 mmol/L
17
Q
Normal fecal potassium
A
75 mmol/L
18
Q
Formula for Osmotic Gap
A
Osmotic gap= 290 - [2(fecal sodium + fecal potassium m)]
19
Q
Are electrolytes decreased or increased in secretory diarrhea?
A
Increased
20
Q
What is the pH of fecal fluid that indicates malabsorption of sugars?
A
<5.6
21
Q
Type of diarrhea that is caused by increased secretion of water.
A
Secretory Diarrhea
22
Q
Enterotoxin- producing organisms that can stimulate water and electrolyte secretion.
A
Escherichia coli
Colstridium
Vibrio Cholorae
Shigella
Salmonella
Staphylococcus
Campylobacter
Protozoa
Cryptosporidium
23
Q
Type of Diarrhea caused by poor absorption that exerts os- motic pressure across the intestinal mucosa.
A
Osmotic Diarrhea
24
Q
The presence of unabsorbable solute ___________ (increases/ decreases) the stool osmolality and the concentration of electrolytes is ___________ (higher/ lower), resulting in an (increased/ decreased) osmotic gap.
A
Increases; lower; increased
25
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)
26
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
27
A sugar that does not need to be digested but does need to be absorbed to be present in the urine.
D-Xylose
28
What type of test can be used to distinguish steatorrhea present in malabsorption and maldigestion?
D-xylose test
29
What is the urine D-xylose level if the resulting steatorrhea indicates a malabsorption condition? (Low or High)
Low
30
Specimen required for quantitative testion of fecal material?
Timed specimen: 3-day collection
31
The brown color of the feces results from intestinal oxidation of ___________ to ____________.
Stercobilinogen to urobilin
32
Stools that appear pale (alcohloic stools) may signify ________.
A blockage of the bile ducts
33
Color of the stool when there is a bleeding originating from esophagus, stomach or duodenum.
Black or tarry stool
34
When there is a bleeding present in the lower GI tract, the color of the stool is ______?
Red
35
Color of stool observed in patients taking oral antibiotics
Green (due to the oxidation of fecal bilirubin to biliverdin)
36
Pale stools associated with biliary obstruction and steatorrhea appear ________ and _________.
Bulky; frothy
37
Preliminary test to determine whether diarrhea is being caused by invasive bacterial pathogens. (Salmonella, Shigella, Campylobacter, Yersinea and enteroinvasive E. Coli)
Microscopic screening
38
Example of bacteria that are not responsible for the appearance of fecal leukocytes.
Bacteria that cause diarrhea by toxin production (Staphylococcus aureus and Vibrio spp.)
39
Stain for wet preparation
Methylene blue (Faster procedure but difficult to interpret)
40
Stain for dried smear
Wright`s or Gram stain (provide permanent slides for evaluation)
41
A test available for detecting fecal leukocytes and remains sensitive in refrigerated and frozen specimens.
Lactoferrin latex agglutination test (The presence of lactoferrin, a component of granulocyte secondary granules, indicates an invasive bacterial pathogen.)
42
Preparation of slides for muscle fiber detection
Emulsifying a small amount of stool in 10% alcoholic eosin (enhances the muscle fiber striations)
43
How long is the slide for muscle fiber detection examined?
5 minutes (the number of red- stained fibers with well-preserved striations is counted)
44
Striations in undigested fibers
Visible striation running both vertically and horizontally
45
Striations for partially digested fibers
Striations are in one side only
46
Striations for digested fibers
None. There is no visible striation
47
What is the indication that the muscle fiber is increased?
Presence of more than 10 muscle fibers counted
48
How long should a specimen be examined after collection?
Within 24 hours
49
The stain routinely used to stain neutral fats (triglycerides), fatty acid salts (soaps), fatty acids and cholesterol during microscopic examination is ________?
Sudan III (Other stains used are Sudan IV and Oil red O)
50
Two parts of staining procedure of fecal fats:
Neutral fat stain
Split fat stain
51
When neutral fats are stained with Sudan III, it appears as __________.
Large orange-red droplets
52
The most frequently performed fecal analysis is ________?
The detection of occult blood
53
What is the amount of blood that is considered pathologically significant?
No visible signs of bleeding may be present with this so __________ testing is necessary
2.5 mL/ 150g; Fecal Occult Blood Testing
54
Methods for detecting fecal occult blood include:
Guaiac
Immunochemical (more sensitive and specific)
Fluorometric porphyrin quantification tests (more sensitive and specific)
55
The most frequently used screening test for fecal blood is ________.
Guaiac-based test fo occult blood (gFOBT)
56
Principle of guaiac- based fecal occult blood test
Pseudoperoxidase activity of hemoglobin (same as the principle of the reagent strip test for urinary blood. However, it uses different indicator chromogen.)
57
Used for routine testing of fecal occult blood
Guaiac-based Occult blood test
58
Increased sensitivity of test used for fecal blood testing leads to _____________ (false positive, false negative)
False positive
59
Obtaining samples from the center of the stool avoids _______________ (false-positive/ false negative) reactions from external contamination during quaiac-based fecal occult blood test.
False-positive
60
How many days will the patient be asked to collect stool samples for Guaiac-Based Fecal Occult Blood Tests?
3 consecutive days
61
Adding hydrogen peroxide to the back of the filter paper slide that contains stool produces what color with guaiac reagent when pseudoperoxidase activity is present?
Blue
62
How long should a specimen be tested after collection for Guaiac test?
6 days
63
Taking Vitamin C before Guaiac test will result to ___________ (false negative/ false positive)
False negative
64
It is the specific for the globin portion of human hemoglobin and uses polyclonal anti-human hemoglobin antibodies.
Immunochemical fecal occult blood test (iFOBT)
65
Does iFOBT require dietary or drug restrictions prior to testing?
No
66
Can iFOBT test detect bleeding for other sources aside from lower GI?
No (it decreases the chance for false- positive reactions)
67
_____________ offers a porphyrin-based FOBT fluorometric test for hemoglobin based on the conversion of heme to fluorescent porphyrins.
HemoQuant
68
The test that measures both intact hemoglobin and the hemoglobin that has been converted to porphyrins.
HemoQuant
69
As hemoglobin progresses through the intestinal tract, bacterial actions degrade it to ________.
Porphyrin
70
Test that is more sensitive to upper GI bleeding (gFOBT/ HemoQuant)
HemoQuant
71
Is porphyrin-based test affected by the presence of reducing or oxidizing substances or the water content of the fecal specimen?
No
72
What will be the result of porphyrin-based test when non-human sources of blood (red meat) are present?
False-positive
73
How many days should the patient avoid eating red meat before undergoing a porphyrin based test.
3 days
74
Used as a confirmatory test for steatorrhea.
Quantitative fecal fat analysis
75
In this test, the patient must maintain a regulated intake of fat (100 g/d) before and during the collection period.
Quantitative fecal fat analysis
76
The specimen for quantitative fecal fat test must be ___________ to prevent any bacterial degradation.
Refrigerated
77
The method routinely used for fecal fat measurement is _________.
Van de Kamer titration
78
Approximately___________ of the total fat content is measured by titration, whereas the gravimetric method measures _______ fecal fat.
80%; all
79
A rapid (5 minutes) and safe procedure for analyzing quantitative fecal fat.
Hydrogen nuclear magnetic resonance spectroscopy
80
Failure to allow stool samples to soak into the filter paper slide for 3 to 5 minutes before adding developer may result in a ______________ (false-negative/ false-positive) result.
False negative
81
gFOBT Interference:
(False Positive/ False negative)
Aspirin and anti-inflammatory medications
False positive
82
gFOBT Interference:
(False Positive/ False negative)
Raw broccoli, cauliflower, radishes, turnips
False- positive
83
gFOBT Interference:
(False Positive/ False negative)
Failure to wait specified time after sample is applied to add the developer reagent
False negative
84
gFOBT Interference:
(False Positive/ False negative)
Iron supplements containing vitamin C
False negative
85
In this method the homogenized specimen is microwaved-dried and analyzed.
1H NMR method
86
Formula for coefficient of fat retention
[(dietary fat – fecal fat) / (dietary fat)] × 100
87
Gold standard for fecal fat testing
Van de Kamer titration
88
Rapid test to estimate the amount of fat excretion
Acid steatocrit
89
Rapid procedure for fecal fat that requires less stool handling by laboratory personnel.
Near-infrared reflectance spectroscopy (NIRS)
90
The result of this test is based on the measurement and computed process- ing of signal data from reflectance of fecal surface, which is scanned with infrared light between 1400 nM and 2600 nM wavelength.
Near-infrared reflectance spectroscopy (NIRS)
91
This test is requested when it is necessary to distinguish the presence of fetal blood or maternal blood in an infant’s stool or vomitus
APT Test (Fetal Hemoglobin)
92
Stool specimen for APT must be ________.
Fresh
93
Enzyme that is more resistant to intestinal degradation and is a more sensitive indicator of less severe cases of pancreatic insufficiency.
Fecal chymotrypsin
94
Enzyme that remains stable in fecal specimens for up to 10 days at room temperature.
Fecal chymotrypsin
95
Enzyme that is capable of gelatin hydrolysis but is most frequently measured by spectrophotometric methods.
Fecal chymotrypsin
96
An isoenzyme of the enzyme elastase and is the enzyme form produced by the pancreas.
Elastase I
97
Enzyme that is strongly resistant to degradation.
Elastase I
98
Enzyme that accounts for about 6% of all secreted pancreatic enzymes.
Elastase I
99
An enzymes that is pancreas specific and its concentration is about five times higher than in pancreatic juice.
Elastase I
100
Is Elastase I affected by motility disorders or mucosal defects?
No
101
Elastase I can be measured through ________.
Immunoassay using the ELISA kit
102
The test is spe- cific in differentiating pancreatic from nonpancreatic causes in patients with steatorrhea.
ELISA test
103
The presence of increased carbohydrates in the stool pro- duces what type of diarrhea?
Osmotic diarrhea
104
Normal stool pH
7-8
105
Increased fecal carbohydrates lowers that pH to below ________.
5.5
106
This test performed using a Clinitest tablet and one part stool emulsified in two parts water.
Copper reduction test
107
Microscopic count of neutrophils in smear stained with methylene blue, Gram stain, or Wright's stain
Examination for neutrophils
108
Pseudoperoxidase activity of hemoglobin liberates oxy- gen from hydrogen peroxide to oxidize guaiac reagent
gFOBT
109
Microscopic examination of direct smear stained with Sudan III
Qualitative fecal fats
110
Microscopic examination of smear heated with acetic acid and Sudan III
Qualitative fecal fats
111
Uses polyclonal anti-human antibodies specific for the globin portion of human hemoglobin
iFOBT
112
Addition of sodium hydroxide to hemoglobin-containing emulsion determines presence of maternal or fetal blood
APT test
113
Emulsified specimen placed on x-ray paper determines ability to digest gelatin
Trypsin
114
Immunoassay using an ELISA test
Elastase 1
