If i have bright red blood from rectum and it stops immediately after using the bathroom, could that not be just hemorrhoids?

It could: Bright red blood per rectum requires medical evaluation. Most of the time it ends up being just hemorrhoids but the seriousness of the possibility that it may be related to a more grave problem behooves an investigation. See your doctor or a gastroenterologist or colorectal surgeon.

Maybe, Maybe not: While rectal bleeding as you describe will most likely be due to either internal hemorrhoids or an anal fissure, there is a significant risk that it could be from a colorectal polyp or cancer. At your age i would strongly recommend colonoscopy. Both the colonoscopy and any hemorrhoid or fissure problem can be managed by a colorectal surgeon.