Your doctor may want to perform any of the following stool tests to determine if your symptoms are due to a colorectal disease:
Fecal occult blood test. A fecal occult blood test checks for hidden (occult) blood in the stool. It involves placing a very small amount of stool on a special card, which is then tested in the doctor's office or sent to a laboratory.
Stool culture. A stool culture checks for the presence of abnormal bacteria in the digestive tract that may cause diarrhea and other problems. A small sample of stool is collected and sent to a laboratory by your doctor's office. In two or three days, the test will show whether abnormal bacteria are present.