Can any of the usual antibiotics cause black stools?

Not aware: Black stools may result by ingestion of materials which contain high iron content. You should, however, make sure that nothing else is going on. Any dr. Can check your stool to make sure that there is no blood present. Also, why are you taking antibiotics? Some can result in changes to the GI tract which are dangerous (i.e., clostridium difficile colitis, and others).