1 Chapter 17 Fecal Analysis Professor A. S. Alhomida Disclaimer uThe texts, tables and images contained in this course presentation (BCH 376) are not my own, they can be found on: uReferences supplied uAtlases or uThe web King Saud University College of Science Department of Biochemistry

2 Fluid Regulation in GI Tract 1.Approximately 900 mL of ingested fluid, saliva, gastric, liver, pancreatic, and intestinal secretions inter the digestive tract each day mL of this fluids reaches the large intestine, and only about 150 mL is excreted in the feces (stool)

3 Fluid Regulation in GI Tract, Cont’d 3.Water and electrolytes are absorbed in both small and large intestines 4.Large intestine can absorb about 300 mL of water, when the amount of water exceeds this amount is excreted in the feces producing diarrhea

4 Fluid Regulation in GI Tract

5 Specimen Collection 1.Routine Specimens Qualitative Testing 2.Timed Specimen Quantitative Tests

6 Component% of Total Weight Water75 Solid25 % of Total Solids Cellulose & Other Indigestive FiberVariable Bacteria30 Inorganic Material (mostly Ca & Ph(15 Fat & Fat Derivatives5 Composition of Feces on an Average Diet

7 1.Macroscopic Screening Color Appearance 2.Microscopic Examination Fecal Leukocytes Muscle Fibers Qualitative Fecal Fats (Steatorrhea) Fecal Analysis Tests

8 Fecal Analysis Tests, Cont’d 3.Chemical Tests 1.GI Tract Bleeding (Occult Blood ) 2.Quantitative Fecal Fat Tests 3.Fetal Hemoglobin (Apt Test) 4.Fecal Enzymes

9 Fecal Analysis Tests Ct’d Fecal Analysis Tests Chemical Tests, Cont’d 5.Carbohydrates 6.Liver diseases 7.Biliary duct disorders 8.Maldigestion and Malabsortion Syndromes 9.Inflammation

10 Fecal Analysis Tests

11 Macroscopic Screening Tests

12 Fecal Screening Tests

13 Fecal Pigments 1.Normal color of feces is influenced by both amount of uroblin present and the kind of food taken 2.Largely vegetable diet gives light-colored stools while one rich in meats gives darker, brown color

14 Fecal Pigments, Cont’d 3.Undigested portions of some vegetables may color the stools Carrots Reddish-brown Spinach Greenish Fruits Bilberries, grayish-purple Milk diet Pale-yellow or Orange

15 Abnormality of Fecal Compositions Steatorrhea 1.Abnormality of absorption and digestion of lipids 2.It occurs when obstruction of flora of bile due to the biliary obstruction 3.Leads to increase fat content of stools

16 Abnormality of Fecal Compositions, Cont’d Occult Blood 1.When bleeding is severe, the stools are dark color 2.Bleeding > 2.5 mL/150 g of stool is considered pathologically significant 3.In intestine, oxyhemoglobin is converted to hematin and porphyrins 4.Only hematin gives +ve results with fecal occult blood test 5.Ulcers and cancers of color give +ve results

17 Occult Blood Tests

18 THE END Any questions?