sophie22 -- From personal experience, I can tell you that bright red blood is almost always a symptom of hemorrhoids or anal fissures. You mentioned that it couldn't be a fissure because you were checked for that ages ago. Keep in mind-- all an anal fissure is is a tearing in wall of the rectum or anus. Kind of like a little cut. They are usually caused by unusually hard stools that are difficult to pass. Hemorrhoids can be caused by this as well...or by lots of diahrreah. Mainly, hemorrhoids are caused by lots of straining. Fissures tend to bleed a lot, whereas hemorrhoids bleed a bit less. Both, however, can produce quite a quantity of blood. Also, it IS possible to have hemorrhoids AND a fissure at the same time. If it keeps up, I'd recommend having your doctor check you out. Hope this info helps!