For me personally, there is nothing I wouldn't be willing to talk about! I lost my modesty so long ago with this DD and having children and everyone looking at that area down below it doesn't even bother me anymore. When I go to the gyno or GI, I just lay back and spread em!
On to your question, I think this is a question you would seriously need to ask your GI. The reason I say this is he would know, thru scopes and what not, how much inflamation and scar tissue you would have it that area, plus any problems with fissures, hemi's, and skin tags. I would think any or all of these could interfere with you having anal due to extreme pain and or tearing.
I also had a boyfriend that requested it and I told him that after having scopes with no anesthesia, that there would be nothing going up there that I wasn't knocked out for. I can't even handle the anal exam my Dr's do.