Fecalysis examination notes

ROUTINE FECALYSIS Stool analysis: analysis: is a series of tests done on a stool sample to help diagnose certain conditions affecting the digestive tract, including infection ( such as parasites, viruses, or bacteria ) , poor nutrient absorption or cancer. SPECIMEN COLLECTION  Patient education Individuals have limited control in the timing of fecal excretion o Collection is highly undesirable for the patient o Verbal and written instructions should be provided along with the appropriate specimen container o  Specimen container Clean, non breakable, sealable and leak proof  o  Type and amount c ollected o Routine fecalysis: peanut size o Quantitative test(3 day fecal collection): container used is paint cans  Contaminants to avoid o Urine: affects detection of protozoa o Tissue paper o Toilet water: contains cleaning agents that affects the chem test) 1. Macroscopic examination  Color: o Brown -normal color (bilirubin) o Green - diet, antibiotics (biliverdin) o Black - GI (upper), charcoal, drugs o Red - GI (lower), drugs  Consistency: o Formed- normal o Hard - constipation (scybala) o Soft - increased fecal content o Watery - diarrhea, steatorrhea  Mucus: Normally not present o If present may indicate: straining during bowel movements , other GIT diseases o 2. Microscopic examination Blood streaks and undigested food - if observed, report as PRESENT   Parasites - if none, report as none seen  Fecal fat o Fecal stains: Sudan III, Sudan IV, Oil Red O ( neutral fat - triglycerides)  Fecal leukocytes and rbc o Normally not present o (+) - invasive/inflammatory, involvement of intestinal wall  PROCEDURE: Emulsify stool in NSS approx diameter of 25 centavo pc. o A good preparation: a density such that newsprint could be read if place under the slide o

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Make another wet mount using Lugol's iodine. (Examine for parasites). Do not air dry.

NORMAL FECES  Brown, soft, well formed  NO blood, pus, bacteria, viruses, fungi, parasites  Tubular shape or cylindrical ( reflecting passage through colon)  Ph 6  6.8 ph - poor absorption of carbohydrates or fat, and problems with amount of bile in digestive tract  < 5.3 ph -poor absorption of sugars  Low level of enzyme ( trypsin or elastase) - -digestive complication of pancreas, problem conditions (cystic fibrosis)  Blood - bleein g indigestive tract  Wbc - bacterial diarrhea.  High level of reducing factor - problem digesting certai sugar (esp sucrase and lipase)  Low level reducing factor - sprue, CF, malnutrition Medications ( colchine - for gout) or oral c ontraceptive may cause low levels o ■

CHEMICAL TEST: FOBT (FECAL OCCULT BLOOD TEST) Principle: pseudoperoxidase activity of hemoglobin 

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Indicators: o Benzidine - most sensitive but carcinogenic so no longer used o Orthotolidine- 2nd in sensitivity o Guaiac - least sensitive, INDICATOR OF CHOICE, eliminates false positive caused of dietary factors Factors affecting testing Improper collection o Contamination ( menstrual or hemorrhoidal blood) o Defective guaiac or peroxide developer o Storage of fecal specimen or slides beyond 6 days o False (+) - salicylates and iron supplements False (-) - antacids and ascorbic acid Procedure o (+) - blue color o Accurate or reliable - (+) blue line, (-) no color change o Invalid - - (+)no color, (-) blue o Add 2 drops peroxide developer after placing 2 thick smears of stool from diff parts of the stool.