Deck 14: Fecal Analysis

Question 1

A negative trypsin test on a fecal sample can indicate which of the following?

A) Pancreatic insufficiency
B) Lactose intolerance
C) Biliary obstruction
D) Duodenal ulcer

Answer 1

A

Question 2

Wet preparations for the detection of fecal neutrophils are stained with:

A) Gram stain
B) Wright's stain
C) Sudan III
D) Methylene blue

Answer 2

D

Question 3

The normal brown color of the feces is produced by:

A) Undigested foodstuffs
B) Urobilin
C) Pancreatic enzymes
D) Cellulose

Answer 3

B

Question 4

Large orange-red droplets seen on direct microscopic examination of stools that have been mixed with Sudan III stain can represent:

A) Fatty acids
B) Soaps
C) Neutral fats
D) Cholesterol

Question 5

Stools from persons with steatorrhea contain excess amounts of:

A) Barium sulfate
B) Mucus
C) Blood
D) Fat

Question 6

The term occult blood in fecal analysis can indicate which of the following?

A) Blood that is produced in the lower GI tract
B) Blood that is produced in the upper GI tract
C) Blood that is not visibly apparent in the stool specimen
D) Blood that produces a black, tarry stool

Question 7

Diarrhea can result from all of the following except:

A) Disruption of the normal intestinal bacterial flora
B) Addition of pathogenic organisms to the normal intestinal flora
C) Increased reabsorption of intestinal water and electrolytes
D) Increased concentration of fecal electrolytes

Question 8

Which of the following pairings of stool appearance and cause does not match?

A) Black, tarry: blood
B) Yellow-green: barium sulfate
C) Pale, frothy: steatorrhea
D) Yellow-gray: bile duct obstruction

Question 9

The recommended specimen for quantitative fecal testing is a:

A) Specimen collected after overnight fasting
B) 24-hour specimen
C) 72-hour specimen
D) Random specimen

Question 10

The presence of amebic dysentery may be suspected when a stool:

A) Has a green color
B) Is coated with blood-streaked mucus
C) Has an extremely foul odor
D) Appears unusually slender

Question 11

A positive lactoferrin latex agglutination test can indicate which of the following?

A) Lower GI bleeding
B) Biliary obstruction
C) Cystic fibrosis
D) Enteroinvasive Escherichia coli

Question 12

When performing microscopic examination of a stool for muscle fibers,the structures that are counted:

A) Are coiled and stain red
B) Contain no visible striations
C) Have vertical and horizontal striations
D) Have horizontal striations and stain blue

Question 13

Microscopic examination of stools for fecal cells provides preliminary information as to the cause of diarrhea because:

A) Neutrophils are present in conditions caused by toxin-producing bacteria
B) Neutrophils are present in conditions that affect the intestinal wall
C) Red and white blood cells are present if the cause is malabsorption
D) Neutrophils are present if the condition is of nonbacterial etiology

Question 14

A pale,frothy looking stool is indicative of:

A) Upper GI bleeding
B) Lower GI bleeding
C) Excess fat
D) Excess carbohydrates

Question 15

All of the following are secreted into the small intestine by the pancreas except:

A) Bile salts
B) Chymotrypsin
C) Lipase
D) Elastase 1

Question 16

Increased neutrophils in a stool sample may indicate that the patient has which of the following?

A) Staphylococcal food poisoning
B) Pancreatic insufficiency
C) Lower GI bleeding
D) Salmonella infection

Question 17

Microscopic examination of stools mixed with Sudan III stain,glacial acetic acid,and then heated will show small orange-red droplets that represent:

A) Soaps
B) Fatty acids and soaps
C) Fatty acids and neutral fats
D) Fatty acids, soaps, and neutral fats

Question 18

The unpleasant odor associated with fecal analysis is caused primarily by:

A) Undigested foodstuffs
B) Bile salts
C) Bacterial metabolism
D) Pancreatic secretions

Question 19

Crystals seen in a stool after it has been mixed with acetic acid,Sudan III stain,and heated may be composed of:

A) Neutral fats
B) Fatty acids
C) Cholesterol
D) Fatty acid soaps

Question 20

A black,tarry looking stool is indicative of:

A) Upper gastrointestinal (GI) bleeding
B) Lower GI bleeding
C) Excess fat
D) Excess carbohydrates

Question 21

False-negative results for upper GI bleeding can be caused by:

A) Degradation of hemoglobin to porphyrin
B) Ingestion of excessive red meat
C) Aspirin and nonsteroidal anti-inflammatory agents
D) Ingestion of excessive folic acid

Question 22

To prevent false-positive fecal occult blood results,patients should be instructed to avoid eating all of the following for 3 days before testing except:

A) Horseradish
B) Chicken
C) Melons
D) Red meat

Question 23

A bloody stool from a neonate should be emulsified in water,centrifuged,and the supernatant tested with:

A) Clinitest
B) Guaiac reagent
C) Gelatin
D) NaOH

Question 24

A bloody stool produced by a newborn should:

A) Have an Apt test performed on it
B) Be tested with guaiac reagent
C) Be emulsified and tested for trypsin
D) Have a Clinitest performed on it

Question 25

State whether or not the following scenarios should be of concern to a laboratory supervisor and why:
In the evaluation of a stool specimen,the results were abnormal in the trypsin test and normal in a chymotrypsin test.

A) Concerned; the trypsin test is more sensitive than the chymotrypsin test
B) Not concerned; chymotrypsin is more resistant to degradation

Question 26

A patient whose stool exhibits increased fats,undigested muscle fibers,and the inability to digest gelatin may have:

A) Lactose intolerance
B) Cystic fibrosis
C) A duodenal ulcer
D) A bacterial dysentery

Question 27

Microscopic screening of a pale,frothy stool from a patient with prolonged diarrhea is performed for fecal neutrophils,fats,and meat fibers.The fecal neutrophil examination result is negative,increased large and small orange droplets are seen in the fat stains,and 10 unstriated muscle fibers are observed.
Based on the information provided,what is the significance of the pale,frothy stool?

A) Biliary obstruction
B) Lactose intolerance
C) Malnutrition
D) Dumping syndrome

Question 28

Tests for the detection of occult blood rely on which chemical reaction?

A) Reaction of hemoglobin with hydrogen peroxide
B) Pseudoperoxidase activity of hemoglobin
C) Reaction of hemoglobin with peroxidase
D) Pseudoperoxidase activity of hydrogen peroxide

Question 29

Before and during collection of a sample for quantitative fecal fats,a patient should:

A) Consume 100 g of fat per day
B) Consume less than 10 g of fat per day
C) Increase usual fat intake by 20%
D) Maintain a soft or liquid diet

Question 30

A stool pH of 5.0 correlates with a:

A) Positive Apt test
B) Negative trypsin test
C) Positive Clinitest
D) Negative occult blood test

Question 31

Microscopic screening of a pale,frothy stool from a patient with prolonged diarrhea is performed for fecal neutrophils,fats,and meat fibers.The fecal neutrophil examination result is negative,increased large and small orange droplets are seen in the fat stains,and 10 unstriated muscle fibers are observed.
Based on the information provided,how long should the slide for muscle fibers be examined?

A) 2 minutes
B) 5 minutes
C) 7 minutes
D) 10 minutes

Question 32

Microscopic screening of a pale,frothy stool from a patient with prolonged diarrhea is performed for fecal neutrophils,fats,and meat fibers.The fecal neutrophil examination result is negative,increased large and small orange droplets are seen in the fat stains,and 10 unstriated muscle fibers are observed.
Based on the information provided,what type of diarrhea is suggested by these results?

A) Secretory
B) Rapid gastric emptying
C) Osmotic
D) Altered motility

Question 33

In the Van de Kamer method for quantitative fecal fat determinations,fecal lipids are:

A) Homogenized and titrated to a neural end-point with sodium hydroxide
B) Measured gravimetrically after washing
C) Converted to fatty acids before titrating with sodium hydroxide
D) Measured by spectrophotometer after addition of Sudan III

Question 34

Microscopic screening of a pale,frothy stool from a patient with prolonged diarrhea is performed for fecal neutrophils,fats,and meat fibers.The fecal neutrophil examination result is negative,increased large and small orange droplets are seen in the fat stains,and 10 unstriated muscle fibers are observed.
Based on the information provided,what is the condition indicated by the increased orange droplets?

A) Inflammation
B) Secretory diarrhea
C) Constipation
D) Steatorrhea

Question 35

Microscopic screening of a pale,frothy stool from a patient with prolonged diarrhea is performed for fecal neutrophils,fats,and meat fibers.The fecal neutrophil examination result is negative,increased large and small orange droplets are seen in the fat stains,and 10 unstriated muscle fibers are observed.
Based on the information provided,absence of what substance most likely accounts for the increased orange droplets?

A) Elastase 1
B) Bile salts
C) Amylase
D) Trypsin

Question 36

The coefficient of fat retention should be at least:

A) 50%
B) 75%
C) 95%
D) 100%

Question 37

State whether or not the following scenarios should be of concern to a laboratory supervisor and why:
Quantitative fecal fat testing performed on a patient maintained on a diet of 100 g of fat per day is 5 g per day.The coefficient of fat retention is reported as normal.

A) Concerned; the normal coefficient of fat is 100%
B) Not concerned; 95% retention is normal

Question 38

When performing the Apt test,a pink color that remains in the supernatant during testing indicates:

A) The presence of fetal hemoglobin
B) Denaturation of fetal hemoglobin
C) Denaturation of maternal hemoglobin
D) The presence of maternal hemoglobin

Question 39

The most sensitive fecal enzyme test for the diagnosis of pancreatic insufficiency measures:

A) Lipase
B) Trypsin
C) Elastase 1
D) Chymotrypsin

Question 40

State whether or not the following scenarios should be of concern to a laboratory supervisor and why:
An Apt test performed on a black,tarry stool is negative for fetal hemoglobin.

A) Concerned; the hemoglobin is already denatured
B) Not concerned; the black, tarry stool indicates the presence of blood

Question 41

State whether each of the following scenarios relates to osmotic diarrhea,secretory diarrhea,or altered motility:
Malabsorption

A) Osmotic diarrhea
B) Secretory diarrhea
C) Altered motility

Question 42

The Apt test should not be performed on a black,tarry stool.

Question 43

The electrolyte content of normal feces is similar to that of plasma.

Question 44

State whether each of the following scenarios relates to osmotic diarrhea,secretory diarrhea,or altered motility:
Shigella dysentery

A) Osmotic diarrhea
B) Secretory diarrhea
C) Altered motility

Question 45

Staphylococcal food poisoning produces secretory diarrhea and increased fecal neutrophils.

Question 46

State whether each of the following scenarios relates to osmotic diarrhea,secretory diarrhea,or altered motility:
Irritable bowel syndrome

A) Osmotic diarrhea
B) Secretory diarrhea
C) Altered motility

Question 47

The neutral fat and split fat stains are confirmatory tests for steatorrhea.

Question 48

A stool that appears black and tarry may be associated with bismuth ingestion.

Question 49

The guaiac test detects both hemoglobin and porphyrin.

Question 50

Steatorrhea is seen in association with decreased elastase 1 in the feces.

Question 51

Tests for quantitative fecal fats include all of the following except:

A) Van de Kamer
B) Lipocrit capillary test
C) Near-infrared reflectance spectrophotometry
D) Acid steatocrit test

Question 52

State whether each of the following scenarios relates to osmotic diarrhea,secretory diarrhea,or altered motility:
Lactose intolerance

A) Osmotic diarrhea
B) Secretory diarrhea
C) Altered motility

Question 53

State whether or not the following scenarios should be of concern to a laboratory supervisor and why:
An unusual number of positive occult blood tests are reported by a new employee in a satellite clinic.

A) Concerned; patients may not be receiving dietary instructions
B) Not concerned; the employee has passed the competency test on performing the test

Question 54

State whether each of the following scenarios relates to osmotic diarrhea,secretory diarrhea,or altered motility:
Staphylococcal food poisoning

A) Osmotic diarrhea
B) Secretory diarrhea
C) Altered motility

Question 55

The D-xylose and lactose tolerance tests are abnormal in persons with malabsorption or maldigestion disorders.

Question 56

State whether or not the following scenarios should be of concern to a laboratory supervisor and why:
A strongly positive stool Clinitest performed on an infant is accompanied by a stool pH of 8.0.

A) Concerned; a low pH coincides with a positive Clinitest
B) Not concerned; the result is strongly positive

Question 57

Microbial infections produce osmotic diarrhea.

Question 58

State whether each of the following scenarios relates to osmotic diarrhea,secretory diarrhea,or altered motility:
Gastrectomy

A) Osmotic diarrhea
B) Secretory diarrhea
C) Altered motility