Careful with that thought process since its the same that the female bodybuilder used in the link I sent and you questioned it yourself lol. Rectal administration allows for substances to be quickly absorbed. An example is alcohol. It bypasses the liver when taken in the bootie and you can get drunk off one or two beers, but the chances of aclohol poisoning are raised exponentially as well. You're right no one knows the correct dishes for oral steroids administered rectally but I wouldn't want to be the guinea pig lol.
Judging from your reference to bootie bumps and your comments in the other thread, i feel safe in assuming you're into experimentation and Rec's so I just advise you to be very careful. I've been there before and some of the consequences do not show up immediately.
Is there even any medical information out there about oral bio-availability of prohormones and steroids? Because if most of these oral steroids have at least over 70% oral bioavailability then it would seem that rectal administration is pointless, aside from bypassing first liver mechanism.
Prohormones I'm certain, wouldn't work rectally, because AFAIK about how they work, they are converted into steroids in the body, which I'm only assuming takes place somewhere in the digestive system (similar to GBL and 14BDO's conversion to GHB). But hell, if you've got a hepatotoxic drug like Anadrol, it's worth researching whether rectal administration is an option.
Rectal administration does allow for quick absorption; it's about 10-15 minutes. It also makes many drugs last longer too (meth and oxycodone for instance, last longer than even intravenous administration), which equals: More drugs in your butt, more money in your wallet.

Many drugs are far more effective rectally and are about 3 times stronger than when taken orally. This is true for MDMA, all stimulants, all thebaine and morphine-based opiates, etc. Whereas with other substances, inserting rectally doesn't make a lick of difference from oral administration (i.e. all benzo's, methadone, LSD, trazodone, etc.)
Okay, I am about to ask a really really dumb question, and this is purely out of curiosity and not something I actually plan on, or was even THINKING about doing... But what happens if you IV steroids? Would it even work? Would it get eliminated from the body very quickly? Would you feel a rush? See, I haven't researched much into how steroids work and don't have much first-hand experience... that's why I'm asking... Are there even any injectable steroids that aren't suspended in oil? I can see how the oil would pose a problem for IV use...