Summarize the following text to main points and sub-points and make detailed explain for them:

ctive invasive stage.  
 Cyst: inactive form resistant to unfavorable environmental 
conditions  
What are the forms of helminthes that can appears in stool?  
1- Ova: that is results from sexual reproduction of helminthes. Eggs 
are recognized by their: 
a. Size. 
b. Color (colorless, pale yellow, brown).  
c. Morphological features. 
2- Larva: the stage that is come from the ova. 
3- Adult stage.  
 
 
 
 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
3.11 Other Findings normally present in Stool  
1. Bacteria: normally non- pathogenic bacteria are found in the stool and 
usually G-ve bacilli such as Escherichia coli, Enterobacter and G +ve 
Lactobacillus sp, Clostridia sp.  
Note: pathogenic bacteria may be found in stool (such as Salmonella, 
Shigella, and Staphylococcus aureus) and this will lead to pus 
formation, stool culture can differentiate between pathogenic and non-
pathogenic bacteria. 
 
Figure (3-42): Different Cells in stool (RBC and WBC) 
2. Yeast: normally stool contain harmless yeast cells as shown in 
figure (3-43) such as blastocystis hominis. 
3. Crystals: normally stool contain triple phosphate, calcium oxalate and 
cholesterol crystal due to food ingestion. 
4. Fibers: normally stool contains many fibers that may arise from clothes 
or undigested plant food. 
5. Air bubbles: normally found and has no clinical significance. 
6. Oil droplets:  normally found, they are very bright and completely 
rounded.  
 
 
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7.GENERAL STOOL EXAMINATION (GSE) 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
7. Undigested food: normally found, it has many shapes as pollen grain, 
bundle of vegetables as shown in figure (3-44).  
 
Figure (3-43): Yeast 
Figure (3-44): Undigested muscle fibber 
8. Charcot-Leyden crystals 
 Formation: Crystals are formed from the breakdown of 
eosinophils and consist of the enzyme lysophospholipase, 
synthesized by eosinophils. 
 Appearance: Crystals are slender and pointed at both endsas 
shown in figure (3-45). 
 Clinical significance: Sometimes found in parasitic infestation 
(especially Amebiasis and Ascariasis) and in cases of ulcerative 
colitis. 
 
 
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7.GENERAL STOOL EXAMINATION (GSE) 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
 
Figure (3-45): Charcot-Leyden crystals. 
3.12 Parasitology 
3.12.1 Entomoeba histolytica 
- 
Amoebiasis is usually transmitted by contamination of drinking 
water and foods with feces (Oral-fecal route). 
- 
Infection can be transmitted through autoinfection (by anal-oral 
contact). 
Diseases 
Entamoeba histolytica causes amebic dysentery and liver abscess. 
Amoebic dysentery 
Disease occurs when amoeba comes in contact with the cells lining 
the intestine. It then secretes enzymes that destroy cell membranes and 
proteins.   
Amoebic dysentery or amoebic colitis is the severe form of 
amboeiasis and it is generally known as invasive amoebiasis.   
Symptoms 
 
 
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7.GENERAL STOOL EXAMINATION (GSE) 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
Amebic dysentery usually starts slowly over several days with 
abdominal cramps, and occasional loose stools, but progresses to 
diarrhea with blood and mucus.    
Blood, mucus and pieces of necrotic tissue become more evident as the 
number of stools increases (10-20 or more per day) and stools will often 
contain little fecal material.    
A few patients may develop fever, vomiting, abdominal tenderness, 
weight loss, or dehydration (especially children) as the severity of the 
disease increases.   
 Note: Bacillary dysentery is a bacterial infection caused by 
Salmonellosis and Shigellosis, in this case No fecal matter is found 
and there are plenty of pus.   
3.12.1.1 Stool analysis  
1- Asymptomatic infections      
Are usually diagnosed by finding cysts shed in the stool as shown 
in figure (3-46).   
 
Figure (3-46): cysts Asymptomatic 
Note: Since cysts are not shed constantly, a minimum of three stools 
should be examined.  
2- Symptomatic infections   
In the case of acute infections gross examination of stool show 
blood and mucus. The motile form (trophozoite) can be seen in fresh 
 
 
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7.GENERAL STOOL EXAMINATION (GSE) 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
feces as shown in figure (3-47). There are abundant RBCs with low 
WBCs.  
Note:  anti-diarrheal drugs should not be taken until stool examination is 
done. 
Diarrheal stools should be examined within 1 hour of collection to 
see 
the 
amoeboid 
motility 
of 
the 
trophozoite. 
Trophozoites 
characteristically contain ingested red blood cells. 
Figure (3-47): Trophozoite of E .histolytica 
3.12.1.2 Disadvantage of stool analysis 
One problem is that other parasites and cells can look very similar to 
E.histolytica when seen under a microscope. 
3.12.2 Giardia lamblia 
Usually transmitted by contamination of drinking water and foods 
with feces (Oral-fecal route) Infection can be transmitted through 
autoinfection (by anal-oral contact).   
Note:  Giardiasis does not spread via the bloodstream, nor does it spread 
to other parts of the gastro-intestinal tract, but remains confined to the 
lumen of the small intestine. 
Pathology 
- Light infection:  
In humans, infection is Asymptomatic in about 70% of the patients.   
- Heavy infection:  
 
 
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7.GENERAL STOOL EXAMINATION (GSE) 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
- Only about 30% of patients exhibit symptoms, in this case Symptoms 
typically begin 1–2 weeks after infection and it includes:   
1. Fatty explosive diarrhea [Steatorrhea]   
2. Loose or watery stool with foul smelling    
3. Epigastric pain, Stomach cramps   
4. Malabsorption Loss of body weight   
3.12.2.1 Stool analysis  
1- Asymptomatic infections   
Finding G. lamblia cysts as shown in figure (3-49) in more formed 
specimens. The cysts are excreted irregularly. Often large number may be 
present for a few days followed by fewer numbers for a week or more. 
Several specimens may need to be examined and a concentration 
technique used.  
2- Symptomatic infections   
The motile form (trophozoite) can be seen in fresh liquid feces. 
Finding G. lamblia trophozoites as shown in figure (3-48) in fresh 
diarrhoeic specimens particularly in mucus. They are often difficult to 
detect because they attach themselves to the wall of the intestine. Several 
specimens collected at different times may need to be examined.   
 
Figure (3-48): G .lamblia (Trophozoite)       Figure (3-49): G .lamblia (cyst) 
 
 
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7.GENERAL STOOL EXAMINATION (GSE) 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
3.12.2.2 Complications of Giardiasis   
Lactase deficiency may develop in an infection with Giardia, 
however this usually does not persist for more than a few weeks, and a 
full recovery occurs, some studies have shown that giardiasis should be 
considered as a cause of Vitamin B12 deficiency, this a result of the 
problems caused within the intestinal absorption system.  
3.12.2.3 Stool analysis  
1- Asymptomatic infections  
Finding G. lamblia cysts in more formed specimens. The cysts are 
excreted irregularly. Often large number may be present for a few days 
followed by fewer numbers for a week or more. Several specimens may 
need to be examined and a concentration technique used.  
2- Symptomatic infections 
The motile form (trophozoite) can be seen in fresh liquid feces. 
Finding G. lamblia trophozoites in fresh diarrhoeic specimens 
particularly in mucus. They are often difficult to detect because they 
attach themselves to the wall of the intestine. Several specimens 
collected at different times may need to be examined.   
3.12.2.4 Fecal Immunoassays for Intestinal Protozoa  
(Antigen Detection, No Centrifugation Recommended)  
It is very important to read the kit information sheet before use.  
 Currently fecal immunoassays are available for G. lamblia, E. 
histolytica, and Cryptosporidium spp.  Fecal immunoassays are more 
sensitive and specific than the routine O&P (Ova and Parasite) exam; 
Especially for G. lamblia.  However, unlike the O&P exam, which 
facilitates the recovery of many different parasites, the fecal 
immunoassays are limited to one or two organisms only. Fresh 
specimens can be stored at 2 to 8C° and should be tested within 48 h. 
 
 
 
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7.GENERAL STOOL EXAMINATION (GSE) 
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ﺩ.ﻣﺤﻤﻮﺩﻋﺒﺪﺍﻟﺮﺯﺍﻕ ﺣﺴﻦ 
3.12.3 Balantidium coli   
Introduction   
Balantidium coli as shown in figure (3-50) are widely distributed in 
warmer climates, which is where human infections most commonly 
occur. The organisms inhabit the large intestine, cecum and terminal 
ileum where they feed on bacteria. The most common hosts being 
humans, pigs and rodents. Human infection is usually from pigs and is 
rare.   
Clinical Disease   
Severe B. coli infections may resemble amebiasis. Symptoms 
include  
 1- Diarrhea, nausea, vomiting, and anorexia. The diarrhea may persist 
for long periods of time resulting in acute fluid loss.   
2- Balantidium coli also have the potentia

Summary :