When discovered early, colon cancer has a 90-percent cure rate. However, because there are no symptoms in the early stages, patients sometimes do not receive a diagnosis until the disease has progressed. A home test that can be used to screen for blood in feces has been reported to have reduced colon cancer related hospital admissions and deaths by one half, and a similar program in Finland caught 40 percent of cancers early. Colon cancer is the third most common cancer in the United States. Symptoms include changes in bowel habits, blood in stool, diarrhea or constipation, unexplained weight loss, exhaustion, and vomiting.
http://www.reuters.com/article/reutersComService4/idUSTRE4AQ6Z820081127