To use a colon test kit, follow any dietary restrictions for three days before beginning the test, collect a stool sample using an enclosed collection stick, and apply it to the test card, according to the American Cancer Society. Test kits require samples from three consecutive bowel movements.
The test kit is a screening test to detect blood in the stool. It's less invasive than other colon cancer tests and done in the privacy of the home. However, a positive result on the test requires further testing using the more invasive methods, explains the American Cancer Society.
The test detects blood in the stool but is unable to determine the source of the blood. In some instances, a positive result indicates stomach bleeding. Eating red meat and taking over-the-counter medications or vitamins within the testing window can trigger a false positive, the American Cancer Society advises.
As of 2015, these tests are more likely to detect cancer if it is present than the test kits of the past. Some individuals who receive the test kit from their doctors never return it. Some don't take it out of fear and others because they are unwilling to follow the dietary restrictions. However, when a doctor gives a patient the kit, that individual is meant to take the sample and return the kit, even if the person doesn't follow the restrictions, explains the American Cancer Society.