All rectal bleeding should be checked out by a Doctor just to be safe. It probably is a hemorrhoid or rectal fissure But there are conditions that occur at any age that can really be serious-- it is the sign of many things --- none good!!
I have a very good friend that had problems for years then she had a colonoscopy because of blood and she had a carpet of literally hundreds of polyps lining her colon --- She had her entire colon removed at 25 yr ---that was 4 years ago.
Don't neglect rectal bleeding at any age. Colon cancer is the third cause of cancer related deaths and it's because people don't get it checked.