Fecal Analysis Flashcards
How much stool the average adult excrete per day?
100-300 mg
About how much of stool is water?
70%
Of the remaining 30% of stool… what are the contents
- 50% is bacteria and cellular debris
- The remaining portion is…
- Vegetable residues
- Small amounts of fat
- Epithelial cells from the GI tract
About how much fluid enters into the GI tract before you have stool?
10 liters
Evacuates feces reflect…
The space and size of the colonic lumen
What is normal colonic transit time?
24-48 hours
Small/dark/hard
Constipation
Voluminous/odorous/floating
Malabsorbed fats or proteins
Loose with mucus
IBS
Loose with mucus and blood
- Inflammed bowel syndrome
- Shingella
- Carcinoma
Skicky/black/tarry
Upper GI tract hemorrhage
Voluminous/watery/little formed material
Non-invasive infection
Pasty/gray/white/little odor
Bile duct obstruction
T/F- Infants and elderly patients with diarrhea can be dangerous and fatal
True
Diarrhea alternating with constipation is characteristic of…
irritable bowel syndrome
How can you check stool for organisms or protoazoa?
Culture it
How can you find viral agents?
Immune electron microscopy
How do you check lactose intolerance?
- By administering pure lactose
- If adequate lactose is present, blood glucose levels should rise in about 60 minutes
- A lactose deficient patient will fail to achieve increased blood glucose levels
- And they will usually have cramping and diarrhea
What occurs in people whose intestinal flora has been killed or disturbed by antibiotics?
C. Diff
How do tests that look for blood in the stool work?
-Use the peroxidase activity of heme derivatives in oxidizing organic compounds
What is the hemoglobin metabolite with peroxidase activity
Hematin
What are also peroxidase enzymes?
Certain plant enzymes and materials derived from myoglobin
This is black tarry stool that is secondary to large quantities of blood in the upper GI tract
Melena
This is small amounts of blood that do not change the appearance of the stool
Occult blood
This is the most widely used indicator to detect occult blood
Gum Guiac
Does overt bleeding or obvious melena require detailed testing?
Nope- but it is important to determine if the red or black pigmentation is actually from blood (like pepto)
When can bright red blood be seen on the stool?
- Hemorroidal bleeding
- Ulcerative colitis
- Friable adenomas
- Superficially eroded carcinomas
How long can melena persist without fresh blood
5 days
How long will a test for occult blood remain positive
Several weeks
What is the hope in screening for occult blood
To detect significant lesions when the are asymptomatic or localized so that treatment can be successful
Causes of upper GI occult blood
- Peptic ulcer
- Erosive gastritis
- Gastric carcinoma
Causes of Lower GI occult blood
- Carcinoma
- Adenomatous Polyps
- Diverticulitis
How are patients usually screened for poop probs?
- Sent home with slides for multiple samples for multiple days
- Avoid meat or aspirin for 1 week prior to testing
How high can false negative results be?
As high as 20% (in patients with colon cancer or large adenomas)
Why do false negatives occur
- Bleeding may be intermittent
- Too much time may elapse before applying the sample and performing the test
When/how are microscopic exams performed?
- For detecting parasites and their ova
- The stool must be fresh
- To identify to the amoeba or other motile parasites, the stool must be warm
What if you see visible striated meat fibers
Proteolysis is inadequate
Should WBC be in the poop
Nope
What does WBC in the poop indicate
Inflammation
If unaltered RBC are present, what does this mean
usually come from the anus or the rectum
blood from higher in the GI tract would have damage to the cells
If you have malabsortion problems, how does this show up?
-Excessive fecal fat excretion
Lipase deficiency increases/decreases the proportion of neural fat?
Increases
Patients with severe malabsorption problems have low/high albumin
Low
Low albumin causes…
- Malnutrition
- Excessive fecal loss
- Edema
