Complete Stool Examination
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Transcript of Complete Stool Examination
Chapter-19 Clinical Investigation
Complete stool Examination
Macroscopic Examination
1- Volume :
Normally less than 200 gm/day unless excessive dietary fibers are ingested
Large volumes indicate diarrhea 2- Consistency :
Normal stools are found but soft
Watery diarrhea is characteristic of bowel infection ( viral or bacterial )
Soft stools are seen in mal-absorption 3- Colour : • The normal colour varies from light to dark brown depending on diet • Black stools may be due to :
- Bleeding from upper gastrointestinal tract melena - Iron intake
• Red blood is usually due to bleeding from the lower alimentary tract and anal e.g. hemorrhoids , ulcerative colitis • Dark green stools are seen in diarrhea due to intestinal hurry . In cholera , the stools are almost watery and conatin epithelial cells and shreds of mucus ( rice water ) . • Greyish white stools in obstructive jaundice ( lack of bile pigments ) • Clay stools are produced by excessive amounts of fat ( Steatorrhea ) 4- colour : + The normal odour is mainly due to products of protein putrefaction ( Indole , skatol ) + Offensive stool are seen in :
- Excessive protein intake - Melena stools - Infective diarrheas , but cholera stools are odourless - Mal-absorption ( stools smell rancid ) - Obstructive jaundice ( absence of bile leads to putrefaction )
5- Other changes : - Mucus : o Normally , stools contain very little mucus o Excessive mucus is seen in :
Chapter-19 Clinical Investigation
Irritable colon ( mucus may be in casts ) Inflammatory conditions Intake of purgatives and antibiotics Neoplasms ( often with pus and blood )
- Pus is seen commonly in : • Dysentry • Ulcerative colitis • Malignancy
Microscopic Examination
1- Examination for red blood cells : excess RBCs is seen in the presence of hemorrhage , inflammation or ulceration . 2- Examination for pus cells : a large number is seen in dysentery and ulcerative colitis . 3- Examination for muscle fibers : undigested muscle fibers indicate deficient digestion usually due to diarrhea 4- Examination for fats :
Normally , present in minimal amounts as neutral fats , ( as oily globules ) fatty acid crystals ( as slender needles ) or soaps ( irregular plaques with rolled edges)
Excess fats indicates deficient digestion , or absorption 5- Examination for parasites : examination should be made from specimens
Bacterial Examination
1- A gram stained film : Is useful to show moniliasis or severe staphylococcal infection 2- Cultures : are made to identify pathogenic bacteria
Normal Amoebic dysentery
Bacillary dysentery
Steatorrhoea
Volume Normal Normal ↑ Large
Odour Normal Offensive Offensive Offensive
Consistency Soft Loose slimy
Watery Loose
Mucus - Excessive Slight +
Reaction Alkaline Acidic Alkaline Alkaline
Undigested food
- ++ + +++
Red cells - ++++ + -
Chapter-19 Clinical Investigation
Pus cells - ++ ++ - Fat content -- - Excessive
Chapter-19 Clinical Investigation
Chemical Examination
1- Occult blood : to detect small amounts , not seen by naked eyes .The test is simple using strips impregnated with benzidine or guaiac which gives blue colour if positive . 2- Fat balance test : the patient is put on a diet containing 50 g fat daily for 1 week . several estimation of faecal fat content is made after the first 3 days :
Normally more than 90 % of the fat is absorbed
Reduced % indicates deficient absorption or digestion of fats