Lab

Question 1

Stool culture

Answer 1

Determine causative organism of diarrhea

Question 2

Quantitative fecal fat

Answer 2

• Fat malabsorption or maldigestion
• 3 day collection & analysis
• Bile acid, pancreatic or malabsorption disorders

Question 3

C. diff assay

Answer 3

• ELISA test- quick results

- Cytotoxicity assay is gold standard: detects toxic effects, expensive & 1-3 days

Question 4

Fungal culture

Answer 4

Determine causative org.

Question 5

Stool O & P

Answer 5

Parasitic infection- repaeat x2 occasion

Question 6

Hemoccult

Answer 6

In clinc or home- FIT or FOBT

- False negative with Vit C, red meat

Question 7

fecal leukocytes

Answer 7

• Stained to determine presence

- infectious or invasive orgs

Question 8

Fecal lactoferrin

Answer 8

Marker for neutrophils

• assessment for IBD
• • indicates inflammatory colitis or enterocolitis

Question 9

Urea breath test

Answer 9

H. pylori- most consistently accurate

- Detection of labeled CO2

Question 10

Gastrin

Answer 10

Increased: Neuroendocrine & gastic tumors, zollinger-ellison, chronic H. pylori
- Decreased: pernicious anemia

Question 11

SAAG gradient

Answer 11

• Classify ascites into portal/ non-portal HTN

- Ascitic fluid albumin

Question 12

H. pylori ab serology

Answer 12

• Non- invasive, detects exposure via IgG
• Cant discriminate between past or current
• Cant monitor response to tx

Question 13

IgA endomysial Ab test

Answer 13

• Celiac disease
• binds to CT and immunofloresces
• falls with reduction in gluten

Question 14

IgA tTG ab test

Answer 14

• Antibody test in celiac

- Less expensive