Stool routine test is taken by the doctor when you have stomach problems. A stool analysis is a series of tests done on stool sample to diagnose certain medical conditions that affect the digestive tract. These conditions can be either an infection, poor nutrient absorption in the body or even cancer. The analysis can help in identifying diseases as well as the cause of symptoms affecting the digestive tract, liver and pancreas. This test is also used for screening colon cancer by checking for hidden blood.