Just to complement and update, you can use suffixes for some URLs only and not all your project - using routes from codeigniter. OP mentions this on his comment but provided no examples.
Here's a example:
http://antsplace.co.uk/url-suffix-in-codeigniter/
I did not do the same thing. In my case, I just needed suffixes for .xml pages
So I only put, on routes.php :
$route['newsfeeds/(:any)\.xml'] = 'newsfeeds/index/$1';
And created a Newsfeeds controller and index function to handle. That's it. That way only URLs with /newsfeeds on segment 1 will allways apply/accept .xml suffix
index controller function is likely many others:
public function index()
{
$this->load->helper('xml');
$this->load->view('xml_view');
}
Don't forget to call header("Content-Type: application/rss+xml; charset=utf-8"); in your site header to properly render xml to this views or you can do this with codeigniter inbuilt function as described in:
https://stackoverflow.com/a/10361155/2387741
And at last this xml helper (docs here) help you translate some characters that need correct formatting on xml to work properly.
I guess this is it. Best regards.