What you can expect

There are several types of fecal occult blood tests, each with a different approach to collecting and testing stool. They include:

• Immunochemical fecal occult blood test (iFOBT, or FIT). The collection method for this test may depend on the manufacturer, but typically, you use a special spoon or other device to collect a sample of stool and store it in a collection container that comes with the test kit.

  The collection container is then returned to your doctor or a designated lab, by mail or in person.

  Immunochemical testing is preferred over the guaiac fecal occult blood test because it's more sensitive. Also, it doesn't require any dietary restrictions before sample collection and testing can often be performed on a random stool sample.

• Guaiac fecal occult blood test (gFOBT). For this test, your doctor typically gives you test cards that are used to collect stool samples from multiple bowel movements.

  You collect a stool sample from each of two or three bowel movements in a clean container, usually taken on consecutive days, and then use an applicator stick to apply a smear of stool to a specific area of a card.

  After the samples are dry, you return them to your doctor or a designated lab, by mail or in person.

• Flushable reagent pad or tissue. You can get this kit at a store without a prescription.

  You place the pad or tissue in the toilet bowl after a bowel movement, usually on three consecutive days. The pads change color when blood is present.

  You then report the changes to your doctor, usually on a mail-in form.

For accurate results, follow the instructions and return the samples promptly.