bungman11's answer is spot on. And no, if done carefully, it doesn't lead to needing a diaper. It certainly hasn't in my case and I've taken toys much larger than a fist.
There is maximum stimulation of everything. It is unique stimulation. You have to learn to relax
The sphincters are stretched. After you get through the sphincters, the intestine is small and re-
quires stretching. There are little attachments that are eliminated when you massage the intestine.
The prostrate has huge pressure on it. It takes time and practice. After you get
anatomy accustomed to massage, it has. no equal. There are little ******* that occur all the time
during *******, and working up to it. I have little o's all along, then one big. The prostate wi be empty
and still contract with ******. Anus, inner lining,sphincters,prostate,bladder,intestine are massaged.
When it is done right, you are not doing it to the anus. The anus sucks your hand in. If it doesn't want to,
it won't invite the hand. There are moments when suddenly your hand is pulled in deeper. The whole experience is very different.
A mans *** is not meant to be analy fisted, go have a sex change and have them put your ******* where your penis is.
Here, I'll do it for you. I'll put a boot in your ***.
its gona hurt like a ***** id guess! you may need a diaper after.
Go out and buy a *****, then buy a bigger one, then buy an even bigger one... and then you take your ******* final and you will have graduated.
Probably reverse childbirth of the butt. I'm just guessing.