There was a task on the old BDSM academy which was aimed at making a man go through a period. Nothing as extreme as you mention but it did involve wearing a pantyliner, using red dye and so on.

I would not advise using anything that is not water as an enema material (which is what you are more or less suggesting) as the absorption of liquids in the colon is a lot more than it is on any other mucus membrane and so any impurities in the liquid are likely to be absorbed into the blood and could cause problems.

Maybe you could use a bit of fake blood smeared around the area, a pantyliner and some figging (ginger root?) to represent the pain?

Then put him in roller skates, hitch him to some dogs and send him off down the beach in a white skirt?