I have something a little smaller to get you started if you're interested!!!!  You can always work your way up from there...LOL.

Anal fisting has long been practiced in the gay community and the do's and don't's are well documented.
Fisting Facts: http://www.winternet.com/~redright/fistfact.htm

and enjoy it.  Contrary to another post, thier poops don't fall out either.  I have fisted two ladies in their ass and they had tremendous orgasms.  You might check in with BJ on her site: bjsextremesex.com  She has give many advise on this and she certainly can take more than a fist.  She will answer questions for you.  

In general, it's a go slow sort of thing.  Tissues need to expand and they take time and repeated stretching to respond.  Just like hanging heavy earings will stretch the ear lobe.  Just don't push to the point of tearing tissues.  You don't want to bleed in this area because fecal matter contains lots of nasty bacteria.

Re:need some advice

Hey D!

Well we both know what a freak I am.  When I worked as a full time Dominatrix fisting was one of My specialties.  I had actually trained men and worked them up to it starting out with My little pinky, it took a little time to work it up to a full fist but eventually we got there.  I know for a fact that you can take a little more then a couple of fingers though.  

I had a BF and he enjoyed for Me to fist him, we had the hottest encounters.  One of My personal fav things is vaginal fisting, gets Me off so hard (A little secret I usually don't share).  I have never had anal fisting but do enjoy the vaginal and have seen men and Women get off pretty hard from anal fisting.  All I can say is take it slow and take what your comfortable with.  If you need a helping hand, let Me know. (wink)  (Getting out the tub of crisco)!

Kisses,
Monica