Experiment No. 3 - ROUTINE STOOL EXAMINATION: PHYSICAL & CHEMICAL PHASE

Question 1

A normal stool consists chiefly of (?), various (?) and a large amount of (?), which are usually nonpathogenic.

Answer 1

undigested food particles
products of digestion
bacteria

Question 2

When diseases occur, (?) increase since the food material is swept out before complete digestion or absorption can take place.

Answer 2

food particles

Question 3

Many of these (?) can be identified either macro scopically, such as seeds, fruit or vegetable skins, etc., or microscopically, such as undigested muscle fibers, vegetable cells, vegetable fibers etc.

Answer 3

food remnants

Question 4

Normal: Color -

Answer 4

yellow or brown

Question 5

Odor:

Answer 5

offensive but excessively

Question 6

Consistency:

Answer 6

soft to semi-formed

Question 7

• Benzidine method

Answer 7

Occult Blood

Question 8

1. Smear a (?) on a strip of filter paper
2. Put drops of (?) at the center of your smear.
3. Add an equal amount of (?).
4. Read the result not after than (?) after the addition of the last reagent.

Answer 8

pea size stool
saturated acetic acid with benzidine powder
3% hydrogen peroxide
2 minutes

Question 9

• very faint blue

Answer 9

Trace

Question 10

• Faint blue

Answer 10

(+)

Question 11

• Distinct blue

Answer 11

(++)

Question 12

• Dark blue

Answer 12

(+++)

Question 13

• prussian blue

Answer 13

(++++)

Question 14

The microscopist should be familiar with the different structures found in the feces such as [?].

Answer 14

trophozoites and cysts of Amoeba, helminth eggs and larvae, RBC, macrophages, WBC, fungi, plant cells (pollen grains and spores), epithelial cells, crystals like Calcium oxalate and triple phosphate, bacteria, plant fibers, root hairs and animal cells are similar to helminth ova

Question 15

Most common errors in the identification of parasites may be due to the following:

Answer 15

(1) Lack of familiarity with the parasites
(2) Cursory examination of the slide and
(3) Confusion of parasite with artifacts.

Question 16

• for trophozoites (seen in watery, bloody stools; motile)

Answer 16

Direct Fecal Smear (DFS) or Direct Wet Mount Technique

Question 17

This is the simplest and moderately efficient procedure for examinations of feces.

Answer 17

Direct Fecal Smear (DFS) or Direct Wet Mount Technique

Question 18

The mixing action of the intestinal tract usually results in an even distribution of parasites in stool.

Answer 18

Direct Fecal Smear (DFS) or Direct Wet Mount Technique

Question 19

DFS preparations from soft, loose and watery specimens should be mandatory.

Answer 19

Direct Fecal Smear (DFS) or Direct Wet Mount Technique

Question 20

It is highly recommended for the detection of motile trophozoites in liquid, diarrheic and bloody mucoid specimens, however, if the number of organisms are few, this method may be of low sensitivity and insufficient to reveal their presence.

Answer 20

Direct Fecal Smear (DFS) or Direct Wet Mount Technique

Question 21

Direct Fecal Smear (DFS) or Direct Wet Mount Technique

1. Comminute approximately 2 mg of feces with a drop of NSS on a clean slide using an applicator stick until a uniform suspension without fibers or gritty materials obtained.
2. Place the cover slip above the preparation and immediately examine under the LPO of the microscope in a systematic method (figure A). Confirm identification under HPO.
3. Wet mounts may be preserved for several hours by ringing the cover glass with paraffin or nail polish.