Antibiotics are ineffective against parasites unless you had something like cryptospordium which would respond to specfic Antibiotics . But crypto is not worms. The only way to know what is going on is to test using the right test - see Metametrix GI Effects stool test.
You could try different products like ParaCleanse by Banyan's or Amazon AP. If those don't work there is always prescriptive drugs such as Albendazole.
But in order to do the right therapy you need to know what you are dealing with, back to the testing issue.