Spiders and session ID's

[jehoshua]

Hi,

Can someone please tell me if a 301 redirect will "force" spiders like msnbot, slurp, googlebot,etc, to re-index a site?

Currently all 3 search engines have session ID's in the results of any searching for the site. We have done all we can to remove the session ID's, but these spiders continue to use/revisit 'old' referenced URL's that contain the session ID's.

Thanks,

Peter