PARA LAB

• Human feces is referred to as STOOL.
• Faeces or Feces is the plural of the latin term faex, meaning RESIDUE.
• Stool is the waste reside of ingestible materials of an animal’s digestive tract expelled through the anus during defacation.
• The composition of stool is ¾ Water, ¼ Solid.
• Undigested and unabsorbed food, intestinal secretions, Mucous, Bile pigments and Salts, Bacteria and Inorganic Material, Epithelial Cells, Leukocytes are found in stool.
• The quantity of stool is influenced by the amount of water and character of food intake.
• A vegetable diet increases the amount of stool by 100-200 grams/day.
• Stool should be collected in a dry, sterilized, wide mouthed container.
• The container should be uncontaminated with Urine or any body secretions.
• A properly named and always fresh sample of stool should be tested.
• Stool samples are to be submitted in covered with a wide mouth.
• The cover prevents attracting insects, specifically flies, since fly eggs might be mistaken for parasites.
• The cover can also prevent fecal odor from filling up the whole area, while the wide mouth allows one to get acquired amount of stool sample from the container with ease.
• Soil, Toilet Water, Urine are potential contaminants of stool.
• The amount of the stool that should be submitted for testing will depend on the techniques that will be performed.
• For Routine Stool Examination, 20-30 grams of formed stools (usually half of the thumb) or 2-3 tablespoons of watery stool specimens are required.
• In cases where the laboratory likes to recover helminthic adults after treatment, it is necessary to submit the whole stool movement.
• Enough stool material will allow performance of a repeat examination or other techniques which will help confirm a diagnosis.
• Macroscopic and Microscopic examination are diagnostic examination methods for stool.
• Macroscopic Examination of Stool Color is Light to Dark Brown due to Urobilin.
• Yellow in Stool can be due to Milk, Fats, Cornmeal, or Unchanged Bilirubin.
• Green in Stool can be due to Spinach, unchanged biliverdin.
• Clay or Putty in Stool can be due to Obstructive jaundice, excess fat in pancreatic disease, barium-X-ray exam.
• Bright Red in Stool can be due to Bleeding in the lower GIT, tomatoes.
• Black or Tarry in Stool can be due to iron supplements, charcoal, digested blood, bleeding in the upper GIT (Ulcers).
• Gray in Stool can be due to Mushy and foul smelling seen in steatorrhea (malabsorption syndrome).
• Stool Odor can be Offensive due to Indole and Skatol.
• Extremely Foul Stool Odor can be due to Putrefaction due to undigested protein.
• Ulcerated and malignant tumors of the lower GIT and in hemorrhages can be seen in Stool.
• Sour or Rancid Stool Odor can indicate gas formation, fermentation of carbohydrates, unabsorbed due to indigestion, highly acidic feces.
• Stool Consistency can be Soft and Formed, Watery Stool, or Excessively hard (Scybalous stool).
• Mucus in Stool can be Translucent and Gelatinous, clinging to the surface of stool, colitis, carcinoma, dysentery (bloody).
• PSEUDOPARASITES ● Air Bubbles ● Starch Granules ● Fungal Spores ● Pollen Grains ● Fibers of meat or plant origin Sample with plant-fiber contaminants (fiber tracheids) A. Tracheids: B. Bacterium: C. White Blood Cell: D. Uric Acid Crystal (Nole Staining): E. Mucoprotein or Albumin (Also Stained Weekly). DIRECT FECAL SMEARS - Direct fecal smears can be used as a quick screening test to check for any intestinal parasite ADVANTAGES & DISADVANTAGES 1. Advantages - Useful for detecting motile organisms - Protozoa are often detected via a direct fecal smear - Quick process
• Microscopic Examination of Stool involves checking for Red Blood Cells, White Blood Cells, Parasites, and Artifacts.
• Red Blood Cells in Stool can be due to Dysentery, hemorrhages, bleeding in the upper or lower GIT.
• White Blood Cells in Stool can be due to Pus cells (Poly or Mono).
• Parasites in Stool can be Trophozites/cyst,ova, worms.
• Artifacts in Stool can be Pseudo parasites - seeds, fungi, haits, various fibers, vegetable cells, pollen.
• Disadvantages of the small sample size limit its usefulness.
• Inaccurate results can occur if the examination finds no evidence of a parasite but the patient actually harbors the parasite, resulting in a false negative result.