Ophelia this is quite an interesting topic that I really think has no simple answer to be honest. A lot of what is done or occurs in our childhood tends to affect our development and shape our outlook on life. With regards to things administered rectally, rectal temps or IM injections, it seems to be more of a trigger into developing a medical fetish related to anal play.
Most individual with admit not liking certain procedures performed on them but the about the age of puberty, those feeling change and you enjoy more enjoyment from having it done.
This thread is very interesting and is worth a look http://www.zity.biz/index.php?mx=forum;ox=display;topic=5843
You have to remember that during your Mom's childhood things like rectal temps, enemas and IM injections were commonly accepted as being normal for health and well-being as everything could be fixed with an enema and a shot of penicillin. With regards to rectal temps, its the most accurate method ( the gold standard ) for trying to fine your core temperature so I'm not surprised an old schooled doctor would use that.
Its seems that modern healthcare is aimed at trying to ensure modesty overrides a proper clinical exam, whether this stems from the increase in medical malpractice lawsuits or from the greater reliance on technology like CT, MRI, Chest Xrays, Ultrasounds, Bloodwork etc remains unknown. Hope this helps, and I really dont believed that we were " psychologically messed up because of everything that was administered rectally and IM injections".