A continuous evolution of modern medicine offers new opportunities for the diagnosis of diseases. Early detection of cancers, in particular, is of paramount importance, as diagnosis in the early stages can significantly improve the chances of recovery. Colorectal and rectal cancers, as well as stomach diseases such as gastric ulcers or stomach cancer, pose serious health problems worldwide. Traditional diagnostic methods, such as endoscopic and palpation examinations, while effective, can often be invasive and uncomfortable for patients. Therefore, researchers are constantly seeking new methods that allow for the diagnosis of diseases through blood tests or other less burdensome techniques. The role of blood tests and stool tests in cancer diagnosis…