Sorry to all the posters who have had such bad experiences. I can identify with a lot of these.
A couple of months ago I had internal examinations done that were really traumatic. Mine wasn't a birth situation, I was having examinations to check for retained productions of conception and possible infection. The doctor said she was going to do a "swab" which I assumed would be like a small cotton swab, as that is what I have had before, and I agreed to that, but then she started to ram in some kind of large plastic cone (sounds like what little sporks was describing!) That was really painful and shocked me because I felt I had no warning since she didn't explain it at all.
I burst into tears and started really really panicking, I was trying to resist it just out of reflex and they just kept saying "relax". When I actually managed to speak I told the nurse that I was finding it really hard because I was raped when I was younger. She didn't really acknowledge what I had said, just kept telling me relax, breathe etc... The doctor did not offer to stop or show any sympathy that I was clearly distressed, just said like it won't take much longer... They held my knees down onto the table to keep my legs open and carry on for about 5 more minutes while I was sobbing :( Afterwards I found that some of the tests they did were not even necessary, e.g. one of the "swabs" with the cone was for chlamidyia which I knew I definitely did not have as I had recently been tested already. If they had asked and explained before doing, they could have saved me some of the unnecessary ones.
The doctor made a comment about why am I reacting like that, how do I deal with smear tests, which made me feel really stupid. I am in my mid 20s, I've only had one smear test before and the smear I had was not traumatic like this as that nurse then was nice, reassuring and told me what was going to happen. These recent internals were much more painful as whatever they used seemed bigger than a normal speculum and it was the shock of having a large foreign object shoved in my vagina without me being informed or consenting 
This experience has been affecting me a lot. As well as having flashbacks to my previous rape while the examinations were happening I have started having them occasionally during sex and I keep feeling really panicky just before penetration even though I know my partner doesn't want to hurt me and would always stop if he was hurting me or I was upset at all.
I'm really angry about how they handled it all because I think anyone would have felt upset and humiliated by that and they need to treat people with more sensitivity, and it is definitely that experience which has triggered my rape flashbacks and putting me back in a much worse place about that again.
I haven't complained about it but I just got a letter telling me to book in for a smear so I think I will have to talk to my GP about all this beforehand to try to ensure I get someone sensitive and understanding for that.