Urinalysis and other Body Fluids - Fecal Analysis

ANALYSIS OF URINE AND OTHER BODY FLUIDS FECAL ANALYSIS OUTLINE • • Introduction Fecalysis o Importance o Components of Normal Stool o Physiology o Common Fecal Test for Diarrhea o Specimen Collection o Macroscopic Screening o Microscopic Screening o Chemical Test INTRODUCTION • • • Examination of feces or stool provides important information for the differential diagnosis of many gastrointestinal diseases and disorders. Hepatic and biliary conditions as well as pancreatic diseases may also be screened through some form of fecal examination. Today, apart from routine macroscopic and microscopic fecal analysis that is able to detect parasitic infections, the most common test performed on stool samples is for the detection of occult (hidden) blood or Fecal Occult Blood Test (FOBT) for initial screening for the presence of colorectal cancer. FOBT is recommended to be performed on all individuals 50 years or older. ` COMMON FECAL TEST FOR DIARRHEA • • • • Secretory Stool cultures Ova & Parasite Examination Rotavirus Immunoassay Fecal Leukocytes FECALYSIS IMPORTANCE • • • • • Early detection of gastrointestinal bleeding Detection of liver and biliary disorders Detection of malabsorption and maldigestion syndrome Inflammation Detection and identification of bacteria and parasite COMPONENTS OF NORMAL STOOL • • • • • • • Bacteria Cellulose and Undigested food stuff Gastrointestinal secretions Bile pigments Cells from the intestinal walls Electrolytes Water PHYSIOLOGY • • Secretory Diarrhea - bacterial, viral and protozoan infections produce increased secretion of water and electrolytes, which override the reabsorptive activity of the large intestine. Osmotic Diarrhea - incomplete breakdown or reabsorption of food stuffs presents increased fecal material to the large intestine resulting in the retention of water and electroytes in the large intestine. • • • • • • • • • • Osmotic Microscopic fecal fats Muscle fiber detection Qualitative fecal fats Trypsin screening Microscopic fecal fats Muscle fiber detection Quantitative fecal fats Clinitest D-xylose tolerance test Lactose tolerance test SPECIMEN COLLECTION • • • • • • Collect the specimen with clean containers like bedpan or disposable container. Transfer the specimen to the laboratory container. Specimen must not be contaminated with urine or toilet water that may contain chemical disinfectant. Containers containing preservatives for ova and parasite must not be used to collect specimens for other tests. Random specimens for qualitative testing are usually collected in plastic or glass containers with screw-capped tops. Timed specimens are required for quantitative testing. It is collected in paint cans. And 3-day collection is the method used. MACROSCOPIC SCREENING MACROSCOPIC EXAMINATION Volume Color Odor Form and consistency Reaction 100-200g/day Light-dark brown Offensive (due to indole & skatole) Soft and Well-formed Alkaline: Increase protein in diet Acidic: Increase vegetables, CHO, and fats in the diet • VARIATION IN COLOR Color Black Red Pale Yellow, White, Gray Yellow Green • • • • • • • • • • • • • Possible cause Upper Gastrointestinal Bleeding Iron therapy Charcoal Bismuth (antacids) Lower Gastrointestinal Bleeding Beets and food coloring Rifampin & Pyridium Compounds Bile-duct obstruction Barium sulfate Milk diet Intake of Rhubarb Biliverdin/Oral Antibiotics Green vegetables • • Vegetable spiral, vegetable hair, vegetable cell, fecal debris Fecal Fats - triglyceride, fatty acid salts, fatty acids, cholesterol Muscle fibers o Undigested - visible vertical & horizontal o Partially digested - 1 direction of striation o Digested - no visible striation CHEMICAL TESTS SUMMARY OF FECAL SCREENING TESTS Test Examination for Neutrophils VARIATION IN ODOR Odor Extremely Foul Putrid Sour/Rancid Possible Cause Increase CHON putrefaction Ulcerated malignant tumors of the lower vowels and in large hemorrhage Increase CHO fermentation Qualitative fecal fats VARIATION IN CONSISTENCY Consistency Soft &Watery Hard & Scybalous (like goat droppings) Gaseous/Fermentative Pea soup Rice watery Flattened/Ribbon-like Bulky/Frothy Mucus/Blood-streaked mucus Possible Cause Diarrhea Spastic Constipation Excessive CHO fermentation Early Typhoid Cholera Intestinal constriction Bile-duct obstruction Pancreatic disorders Colitis Dysentery Malignancy Constipation MICROSCOPIC SCREENING • • • Body Cells o Few epithelial cells o RBC - lesions of colon, rectum or anus; in case of amoebiasis o WBC ▪ ulcerative condition ▪ bacillary dysentery ▪ other inflammatory states o Macrophage ▪ amoebiasis ▪ ulcerative colitis ▪ bacillary dysentery Crystals o Normal Crystals ▪ Triple phosphate ▪ Calcium oxalate ▪ Fatty acids crystals o Abnormal Crystals ▪ Charcot-leyden crystals ▪ Hematoidin Parasite Occult Blood Apt Test Trypsin Clinitest Methodology/Principle Microscopic count of neutrophils in smear stained with Methelene blue, Gram stain, or Wright’s stain Microscopic examination of direct smear stained with Sudan III Microscopic examination of smear heated with acetic acid & Sudan III Pseudoperoxidase activity of hemoglobin liberates O₂ from Hydrogen peroxide to oxidize guaiac reagent Addition of Sodium Hydroxide to hemoglobin-containing emulsion determines presence of maternal or fetal blood Emulsified specimen placed on X-ray paper determines ability to digest gelatin Addition of Clinitest tablet to emulsified stool detects presence of reducing substances Interpretation 3/hpf indicated condition affecting intestinal wall 60 large orangered droplets indicates malabsorption 100 orange-red droplets measuring 6-75 µm indicates malabsorption Blue color indicates gastrointestinal bleeding Pink color indicates presence of fetal blood Inability to digest gelatin indicates lack of trypsin Reaction of 0.5 g/dl reducing substances suggests CHO intolerance