Stool Analysis What is the stool or feces? 1. Waste residue of indigestible material (cellulose during the previous 4 days) 2. Bile pigments and salts 3. Intestinal secretions, including mucus 4. Leukocytes that migrate from thebloodstream 5. Epithelial cells that have been shade 6. Bacteria and Inorganic material(10-20%) chiefly calcium and phosphates. Undigested and unabsorbed food.
Random Collection1. Universal precaution2. Collect stool in a dry,clean container3. uncontaminated with urine or other body secretions, such as menstrual blood4. Collect the stool with a clean tongue blade or similar object.5. Deliver immediately after collection
Ova and parasites collection1. Warm stools are best for detecting ova or parasites. Do not refrigerate specimen for ova or parasites.2. If the stool should be collect in 10 % formalin or PVA fixative, storage temperature is not critical.3. Because of the cyclic life cycle of parasites, three separate random stool specimens are recommended.
Enteric pathogen collection1. Some coliform bacilli produce antibiotic substances that destroy enteric pathogen.Refrigerate specimen immediately.2. A diarrheal stool will usually give accurate results.3. A freshly passed stool is the specimen of choice.4. Stool specimen should be collected before antibiotic therapy, or as early in the course of the disease.5. If blood or mucous is present, it should be included in the specimen
Interfering factors1. Patients receiving tetracyclines, anti-diarrheal drugs, barium, bismuth, oil, iron , or magnesium may not yield accurate results.2. Bismuth found in toilet tissue interferes with the results.3. Do not collect stool from the toilet bowl.A clean, dry bedpan is the best.4. Lifestyle, personal habbits, environments may interfere with proper sample procurement.
Normal values in stool AnalysisMacroscopic examination NormalvalueAmount 100-200 g / dayColour BrownOdour Varies with pH of stool and depend on bact- erial fermentationConsistency Plastic, not unusual to see fiber, vegetable skins.Size and shape FormedGross blood,Mucous,Pus, Parasites None
Normal values in stool analysisMicroscopic examination Normal valuesFat (Colorless,neutral fat (18%)and fatty acidcrystals and soaps)Undigested food None to small amountMeat fibers, Starch, Trypsin NoneEggs and segments of parasites NoneYeasts NoneLeukocytes None
Normal values in stool analysisChemical examination Normal valuesWater Up to 75 %pH 6.5-7.5Occult blood NegativeUrobilinogen 50-300 µg/24hrPorphyrins Coporphyrins:400-1200µg/24hr Uroporphyrins:10-40 mg/24hrNitrogen <2.5 g/24hr
Normal values in stool analysisChemical examination Normal valuesBile Negative in adults:positive inchildrenTrypsin 20-950 units/g( positive insmall amounts in adults; present ingreater amounts in normal children.Osmolarity used 200-250 mOsm withserum osmol- arity to calculateosmotic gapSodium 5.8-9.8 mEq / 24hr
Normal values in stool analysisChemical examination Normal values Chloride 2.5-3.9 mEq / 24 hr Potassium 15.7-20.7 mEq /24 hr Lipids ( fatty acid) 0-6 g / 24 hr
Clinical Implications1. Fecal consistency may be altered in variousdisease states a. Diarrhea mixed with mucous and red blood cells is associated with 1. Typhus 2. Typhoid 3.Cholera 4. Amebiasis 5. Large bowel cancer
Clinical Implicationsb. Diarrhea mixed with mucus and white blood cells is associated with1. Ulcerative colitis 2. Regional enteritis3. Shigellosis 4. Salmonellosis 5. Intestinal tuberculosis
Clinical Implications C. ”Pasty” stool is associated with a high fat contentin the stool:1. A significant increase of fat is usually detected on grossexamination2. With common bile duct obstruction, the fat gives thestool a putty- like appearance.3. In cystic fibrosis, the increase of neutral fat gives agreasy, “butter stool” appearance.
Stool OdorNormal value Varies with pH of stool and diet. Indole and sketole are the substances that produce normal odor formed by intestinal bacteria putrefaction and fermentation.Clinical implication.1. A foul odor is caused by degradation of undigested protein.2. A foul odor is produced by excessive carbohydrate ingestion.3. A sickly sweet odor is produced by volatile fatty acids and undigested lactose