EXAMINATION OF FECAL SAMPLES

• IMPORTANCE OF FECALYSIS

  1. To detect the presence of parasites
  2. For the detection of evidence of malfunction of some parts of the GIT, liver and pancreas
  3. For the detection of GIT bleeding
  4. For the detection of excessive fats in stool (steatorrhea)
  5. Used as a clue in medical and surgical diagnosis.
• PHYSICAL EXAMINATION

  FORM & CONSISTENCY

  • NORMAL: soft to formed
  • OTHER FORMS:

  1. Very soft and watery - seen in diarrhea and administration of saline cathartic
  2. Excessively hard and scybalous - constipation due to lack of mucus
  3. Rice water stool - cholera
  4. Pea soup stool - early typhoid
  5. Flattened or ribbonlike - syphilis, spastic colitis and obstruction at the lower portion of the colon
  6. Butter like - fibrocystic disease of the pancreas
  7. Gaseous and fermentative - excessive carbohydrate fermentation
• CONSISTENCY

  1. HARD - Cannot be punctured with an applicator stick
  2. FORMED - Maintains shape, can be punctured
  3. SEMI - FORMED Bottom side flattens in the container
  4. SOFT - Can be cut with an applicator stick
  5. MUSHY - Can be reshaped with applicator stick
  6. LOOSE - Stool shapes to container
  7. DIARRHEIC - Stool will flow slowly out of the container
  8. WATERY Fluid - like stool pours out of the container
• BRISTOL STOOL CHART

  Type 1 - Separate hard lumps, like nuts. Hard to pass

  Type 2 - Sausage shaped but lumpy

  Type 3 - Like sausage but with cracks on the surface

  Type 4 - Like sausage or snake, smooth and soft

  Type 5 - Soft blobs with clear-cut edges. Passed easily

  Type 6 - Fluffy pieces with ragged edges, a mushy stool

  Type 7 - Watery, no solid pieces. Entirely liquid
• COLOR

  • NORMAL: light brown to dark brown due to stercobilin
• 1. YELLOW

  • Administration of santonin and senna
  • Seen in antibiotic therapy
  • Increased milk diet (infants)
  • Presence of unchanged bilirubin
  • Obstruction to bile flow
  • Large amounts of cornmeal
• 2. LIGHT CLAY OR PUTTY COLOR

  • After ingestion of Barium meals
  • Due to the absence of bile pigments
• 3. REDDISH OR BLOODY

  • Bleeding in the lower GIT
  • Undigested beets and tomatoes
• 4. DARK RED/CHOCOLATE BROWN

  • Bleeding in the upper GIT
  • Increased intake of coffee, chocolate & cherries, black berries
• 5. BLACK/TARRY

  • Digestion of blood due to bleeding in the upper GIT
  • Increased intake of iron, bismuth & charcoal
• 6. GREENISH

  • Amoebiasis
  • Ingestion of vegetables like spinach
  • Presence of unchanged biliverdin
• 7.GRAY

  • Cocoa and chocolate produce dark gray stools
  • Blueberry juices, carbon, iron and bismuth: gray to pitch black feces
  • Light gray: undigested fats, following inadequate bile secretion
  • Malabsorption syndrome
• 8. MISCELLANEOUS

  • Bizarre colors: drugs
  • Whitish discoloration or speckling: Aluminum hydroxide preparation & barium
  • Blue: Methylene blue & dithiazanine
  • Orange red: Pyridium
• ODOR

  • Tryptophan  indole & skatole
  • Dependent: Amount of meat in the diet & Putrefactive bacteria

  NORMAL: foul to offensive (BIS)

  1. SOUR ODOR:

  • Normal for infants: fatty acids in ingested milk
  • Adults: steatorrhea

  2. SOUR ODOR TO A PUTRID ODOR:

  • Severe diarrhea in children

  ABNORMAL:

  1. PUTRID – ulcerate & malignant tumor of the lower bowel
  2. SOUR/RANCID – gas formation, unabsorbed fatty acids
  3. EXTREMELY FOUL – ulcerations of intestines & rectum, malignancy, syphilis, dysentery & necrotic lesions of the intestines
• CHEMICAL EXAMINATION

  OCCULT BLOOD

  • Detected only by chemical means
  • Presence indicates hemorrhage in the intestinal tract

  May be seen in the following:

  1. Benign peptic ulcer
  2. Esophageal, stomach, duodenal bleeding
  3. Hemorrhoids
  4. Liver cirrhosis
  5. GIT carcinoma/rectal carcinoma
• LABORATORY TESTS FOR OCCULT BLOOD

  1. Benzidine test
  2. Guaiac’s test
  3. Hematest – kit we use in the lab
• CAUSES OF FALSE POSITIVE RESULTS

  1. Peroxidase activity of substance or fecal material

  • Bacteria
  • Fresh fruits
  • Vegetables
  • Cauliflowers
  • Chlorophyll of plants

  2. Iron in the diet

  3. Myoglobin in ingested meat
• CAUSES OF FALSE NEGATIVE RESULTS

  1. Large amount of Vitamin C - Interferes in the oxidation of chromogen
  2. Breakdown of blood and its constituents
  3. Hemorrhage in the upper GIT
  4. Technical errors
• PATIENT PREPARATION PRIOR TO OCCULT BLOOD TEST

  • Meat-free diet for 3-5 days prior to the test
• MICROSCOPIC EXAMINATION

  The following may be seen:

  • Trophozoites & cysts of amoeba
  • Helminth eggs & larvae
  • Red blood cells - due to hemorrhagic disorder, ulcers and contamination
  • Macrophages - present in bacterial or parasitic infection
  • White blood cells - indicative of inflammation
  • Fungi
  • Plant cells, pollen grains & spores
  • Epithelial cells
  • Triple phosphate & calcium oxalate
  • Bacteria
  • Plant fibers
  • Charcot Leyden crystals