Uncertain. Get eval. Possible causes of blood in stool include: fissures, fistulas, hemorrhoids, cancer, ulcers, infections, inflammation, Diverticular disease & Angiodysplasia. Get evaluated if more than a one time occurrence.
Depeds. Could be anything frm hemorrhoids, fissure, colitis, colon polyps or colon cancer. Could also be duodenal ulcer. Get it thoroughly evaluated. Age is irrelevant when it comes to bleeding. It is not normal. Be safe and seek an expert.