Had a bit of blood in one stool days back then it went a way. today it is there again. should i be worried? it's light blood attached to the stool

Bloody stool: Blood in the stool is a sign of disease in the colon or rectum. Most often, if it is "red" it is from the lower GI tract from hemorrhoids--meaning in or near the rectum. If it is dark or black, it has been in the GI system for a while, and its source is more remote. A good exam is in order and the source of the blood should be determined.