"Autogynephilia." I learned that new-to-me word. It's related to m/f crossdressing, but goes beyond a guy just enjoying dressing in women's clothes. It encompasses the male desire to imagine himself as herself, which I guess must be the core of m/f transgenderism. I'm told one of the things guys desire in that role is to experience, as closely as possible, the sensations that accompany being female. Some actually want to have the experience of having miserable period cramps!
Enter cold enemas. While for myself I usually am seeking the triggering of a powerful and delightful orgasm from cold water in my bowels, I have discovered it's possible to induce genuinely painful cramping that very closely mimics the awful sensations of bad monthly cramps. As a woman I hate menstrual cramps, but I suppose that for a guy who genuinely wants to experience what it is like to live in a female body it's a part of the overall experience. Cramps suck, but may you enjoy them.
Start by flushing out your colon in the usual way. Insert a large tampon in the rectum. (I find Playtex Ultra to be the best of the bunch for this purpose.) Fill an enema bag with COLD water (not iced, but around 60 *F or15*C). Work the well lubricated noz up past the tampon and slowly inject two liters into your colon. I prefer lying on my bed for this purpose. Run the water in slowly, getting it as high into your bowels as possible. I find a fast injection of cold water into your colon will more likely induce an orgasm, while a slow one will more likely induce painful cramping. Snug down on the tampon string, put an absorbent pad to catch leaks, (this is an opportunity to "ride the rag" of a thick menstrual pad if you wish, but it must be placed farther back to catch rectal leaks.)
If I'm trying to hold a full two liters I find a tight high girdle really helps, but isn't absolutely necessary. Now go sit at a computer and enjoy whatever porn turns you on. In a few minutes you will begin to experience really hurty cramps in your abdomen. Lucky fellows, you guys can choose to end the misery by just pulling the plug and pooping out the cold water, while we have no choice but to hurt every month until it doesn't hurt any more. Does it feel exactly like menstrual cramps, no, but it is a pretty darn close approximation. It seems strange to say enjoy the pain, but enjoy the pain.
Hugs,
~Diane