probably you mean something like following ?
http://www.dokuwiki.org/plugin:discussion
The Discussion Plugin adds a discussion section after your wiki page for user comments. This is useful to separate page content and the discussion thereof and also, if you don't want to give normal users the right to edit the page but still want user contributed notes. A second component of this plugin shows a list of all pages in a namespace with a discussion section (called discussion threads) ordered by most recent comments. This allows you to create a very simple discussion forum in your wiki.