Tests for occult bleeding are used to discover hidden bleeding ( gastrointestinal ) to differentiate between melena melena and seat layout . Certain medications such as iron , bismuth , and could seat can darken the diagnosis wrong melena .
Also, these tests are very important for early detection of colorectal cancer , as 80 % of patients with these diseases the occult bleeding . On the other hand , a single positive test does not necessarily indicate gastrointestinal bleeding or colorectal cancer . To be considered positive , the test should be repeated at least 3 times in a certain period , during which the patient will follow a specific diet recommended in detecting occult bleeding . However, a positive test in these circumstances is not necessarily indicative of colon cancer but can also be caused by gastrointestinal bleeding gastric ulcer , diverticulosis , etc. .Are used as screening tests (eg , in the UK, after a certain age , repeat every 2 years for early detection of colorectal cancers ) .
The tests are easy to perform , consisting in the addition of certain substances ( or a paper impregnated with such material ) over the stool sample , appeared almost immediately a specific color in the case where the blood lost through the stool is more than 5 ml per day .
These analyzes are important because occult bleeding are in very small quantities , indepistabile human eye, but repeats can lead to severe anemia .
- collecting glass jar
- tongue depressor or any other specific instrument collection that you have lab
- specific substance or substances soaked paper ( the test kit )
confirming patient identity
put gloves and harvested according to the sampling procedure of seat
will go immediately to the laboratory sample or if we harvest kit will observe the prospectus of Use
Wash hands well and groom themselves if the patient is immobilized
announcing the doctor for any occurrence of blue or green coloring on the paper test
Special considerations :
ensure that the sample collected is not contaminated with urine solution, soap , toilet paper ( it contains bismuth and affect the outcome ) then use test kit as described
test is done in different portions of the seat as occult bleeding from the upper gastrointestinal tract is not present in all seat format , and that of colorectal cancer can usually only occur in the first portion of the seat
will check the expiry date of the test kit
patient will be instructed to follow a diet rich in fiber, no meat, no fish, no turnips , kale , etc. For all these things can give false positive reactions . Diet should be kept between 48-72 hours before the test
Also, with 48-72 hours before testing , discontinue medication that can affect the outcome (iron , potassium indomethacin , steroids )
if the patient is alone at home testing, will be carefully instructed regarding the procedure
one of the newest and easy tests for occult bleeding test is called ” coloring ” . It is indicated for patients who make their own tests do not require collection of stool samples and is very easy to test and interpret. Thus , the patient should follow a specific diet with 48-72 hours prior to testing. The patient is taught to remove any disinfectant toilet and draw water 2 times after removal of toilet disinfectant . After defecation , is instructed not to throw toilet paper into the toilet bowl until the reading test because of its bismuth content can affect the outcome. In the 5 minutes immediately after defecation , will undo kit tester test and throw the toilet , which will float on the water surface of the toilet . The patient will read the result after 15-30 seconds . If the seat is occult bleeding , the tester will turn blue or green. The patient will have to repeat testing three different chairs , to write down the results and submit them to the doctor.