Can a tooth have 2 root canals?

An x-ray shows that one of my teeth which already has a root canal might have some infection, and my dentist has referred me to an endocontics dentist. My dentist states that a second root canal might be needed, but is not sure whether is possible, or what would be the consequences. . Please llet me know whether a second root canal can be made on a tooth and, if so, what would be the results. . If not, what would be the -solution?