Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Remove ads
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards




share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

GI Stool Studies

Gastroenterology

QuestionAnswer
iFOBT immunochemical; specific for human globin; fewer false pos
FOBT guidelines CLIA waived; 3 serial stools; avoid red meat & >250 mg vitamin C x 3 days; avoid ASA >325 mg x 7 days
FOBT timing s/b after 3 days; at least 3-5 min; within 14 days
FOBT other sources of false pos EtOH, anticoag, steroids, CTx, iodine prep
Fecal WBC: methylene blue; PMNs (poss macrophages); invasive organisms & IB disorders; >1 g spec clean dry container (Cary Blair); not done on pts in hosp >3 days
Fecal WBC: present for : shigella, campy, EIEC (poss salmonella, vibrio, yersinia, C diff)
Poss false negs in fecal WBC E. histolytica; CMV
Predominant causative enterotoxin for pseudomem colitis C diff toxin A; recent Abx tx; do ELISA test; may need serial stools
C diff toxin assay specimen criteria specimen >5 ml (fridge if >1 hr); pt 5 soft/liquid stools /24 hr; submit 3 specimens on 3 different days
Gold std for pseudomem colitis tissue cx (rarely done; usu do toxin assays); if done, need bx and anaerobic cx
3 most commonly screened bac pathogens Salmonella, Shigella & Campylobacter (4 other important patho: Vibrio, Aeromonas, Yersinia & E. coli O157:H7; all cx except E Coli: testing stool for toxin)
Bac stool cx specimen fresh/unpreserved <2 hr; or preserved (Cary-Blair) <96 hr; not in pts hosp > 3 days
O&P specimen parapak; if fresh: <2hr (liquid) or <4hr (formed); 1 spec/pt/wk or 1/hosp; reject if immunocompetent >6 yo or hosp >3 days
Acid fast stain for: crypto and cyclospora
IFA: for: Giardia (uses monoclonal Ab); also avail for Crypto
Rotavirus F/O trans; Jan-May; kids 6 mo-2 yr; 1-3 d incub, lasts 5-8 d; EIA: 1 mL stool, fridge if delay
PCR for Norovirus ONLY performed for epidemiologic reasons
Fecal fat screen for malabsorption dz; gold std: Quant: high-fat diet x2d before & during collection (72 hrs); normal <7g/24hrs; Qual: Sudan stain (high-fat diet): Pos = multiple fat drops seen (40x obj)
Tests for C diff: Cytotoxin B in stool is definitive (takes 24h); rapid ELISA for enterotoxin A & B faster but less sensitive
Created by: Abarnard