1. Chapter 6 Stool tests
Stool examination is a basic method for getting clues of inflammation, bleeding, obstruction, tumor and parasite infection in gastrointestinal tract and digestive system in clinic. This part of tests include the general property of stool, microscopic examination , chemical (occult blood) test and bacteriological tests.

2. General property of stool
Microscopy
Occult blood test
Bacteriological examination

3. General property of stool
watery stool: infectious and non-infectious diarrheas
mucus stool: inflammatory diarrheas
pyohemochezia stool: bacterial dysentery, ulcerative colitis, Crohn’s disease,rectum carcinoma, colon carcinoma
hematochezia stool: bloody diarrhea, hemorrhoid ischemic colitis, amebie dysentery, rectocolitis
melena or tarry stool: a sign of bleeding from an upper digestive tract: gastric ulcer, carcinoma of stomach
kaolin stool: biliary obstructio

4. Microscopy Cells: WBC:normal 0~1/HP, >15/HP inflammation
RBC:normal:0, RBC (+~+++) : dysentery, carcinoma of GI, ulcerative colitis
macrophage:normal: 0, (+): colitis , bacterial dysentery
tumor cell: colon carcinoma, rectum carcinoma
Food residue:
Ovum of parasite : roundworm, hookworm , tenia

5. Occult blood test
GI bleeding is a common clinical problem. Blood loss ranges from occult bleeding of which the patient is unaware to massive bleeding that anyone would notice( melena or bloody stool). Positive occult blood test is usually due to chronic GI blood loss, both upper and lower GI lesion such as peptic ulcer, stomach carcinoma, and colon carcinoma. It is a screening test for digestive carcinoma especially for elderly people .

6. Case analysis
History and physical examination: This patient was a 68-year-old man. For the previous 3 months he had complained of incresingly severe dizziness, shortness of breath, weakness and melena stool. On admisson to the hospital , the body temperature was 37.6 C. Slightly enlarged lymphnodes were palpable in the rght axilla and posterior cervical areas. The spleen and liver are not enlarged.

7. Laboratory data: Hb 75g/L, WBC 15×109/L, PC 80×109/L, stool: tarry and soft, RBC 1~3/HP, WBC 2/HP, no special cell was found.
Question:
What do you think this patient probably suffer from ?
What do you plan to do next?
why does this patient had developed medium anemia?