My 13 year old son just found blood in the toilet bowl when he had a bowel movement. The feces was a long, brown, tubular piece - did not look particularly hard or discolored. There seemed to be no blood mixed in with it. The water in the bowl had settled; it was clear at the surface, then bright red like raspberry tea below that, then darker red down in the bottom of the bowl. My son is in great health, very athletic, slim, eats well (albeit light on the fiber); he has no pain and there is no sound of abdominal growling . He did not strain making the stool and felt no pain as it passed. He is in no distress and in fact is in a great mood. Any ideas?