If you are enrolling in a forensic science program, make sure the program is accredited and includes at least 24 semester hours of chemistry or biology and math, as well as all the prerequisites for medical school.
Frederick R. Jelovsek MD. When the doctor does a rectal exam and smears a stool sample on a card to test for blood in the stool, or gives you a paper to drop into the toilet to look for a color change, this is known as testing for occult gastrointestinal bleeding.
Melena is a term that describes a particular appearance of blood in stools. This term describes stools that are black, tarry and often foul-smelling because of the presence of blood from the upper gastrointestinal tract.iagnostic tests that might be performed include blood tests, stool cultures and X-rays. Testing the stools is important because in certain specific situations, stools can take on the appearance of melena even if no bleeding is present.