I noticed in my stool once two months ago. Since then, nothing. Should I still be screened? I bleed (red) regularly when I go to the bowel. I do not have hemorrhoids. My doctor tells me not to worry. By the editors of Allodocteurs.fr Answers with Professor Julien Taieb, gastroenterologist and oncologist: "A single episode of blood in the stool from the age of 50 needs to be referred.