Garbovatwin - the ileostomy uses the small intestine - so the output tends to be more liquid. Mine varied from total liquid to a toothpaste like consistency - how's that for TMI!!!
When you're on chemo and/or radiation, it really does a number on what comes out - whether you're pooping into a bag or out your bottom.
With a colostomy, you're using the colon for the ostomy part. Since one job of the colon is to absorb fluids, the output is more solid. I've never had a colostomy so I can't share all the gorey details of exactly what that output is like.
I know you have concerns about what your future may hold as far as a potential ostomy. If you haven't browsed the UOAA (United Ostomy Associates of America) chat group, definitely check it out sometime. I think if most people have a choice - as far as a permanent ostomy, they would opt for a colostomy as it is a little less maintenance. Also, with the ileo being more liquid, if that liquid output gets on your skin, it burns like crazy. The reason it would get on your skin is usually a problem with getting a good seal on your appliance. Some people, however, don't have a choice and end up with a permanent ileostomy due to problems with their colon. Here's a link to the UOAA web-site....
http://www.uoaa.org/forum/viewforum.php?f=2