Had you had done major damage you wouldn't be posting here, you would be bleeding out, in definite pain and most likely either lying on the bed wondering if you should be calling an ambulance (over the fear of being found out for what you had done) or at Hospital ER.
Let us take look see at the inside of the human body.
Please to note that there is the rectum, and a fairly large 'tube' of material called the lower intestine - colon. Now that can move and shift about under gentle pressures, this is how they manage to take a fist and half an arm (all the way up to the elbow) but the fister moving and straightening out the colon/lower intestine.
Most likely what you did was move your colon a bit to give enough 'straight away' for the toy. It should right itself on its own. there are connective tissues that hold everything basically in place, these are highly elastic and will 'shift' to allow the passing of fecal matter and other stuff through the intestines - they allow allow for you to bend over, stand on your head, float in micro-gee without your guts twisting up.
If you tore any of that connective tissue you could run into a problem "twisted gut" - when dogs get it they don't live much longer than a few days. When horses get it, they put the horse down and send it to the glue factory. When humans get it can be a lengthy procedure. Depending on the nature of the twist and the cause will tell a doctor what to do:
http://digestive.niddk.nih.gov/ddiseases...omiccolon/ gives lots of data on the whole subject.
The rectum is 6 to 8 inches long. So stick with toys that are about that long, this is 'safe'.
One thing you can 'readily' do is shove something to fast up there and the item goes through the wall of the colon at the top of the rectum, instead of the colon moving 'fast enough' to accommodate the item.
Had this happened you would either be laying on the bed in an expanding pool of blood worrying about dying from bleeding or dying from embarrassment as you tell the doctors why you punctured your colon, or you would be at hospital in ER right now. the pain is phenomena in most cases, and the amount of blood can make a woman's heavy menstruation look like a trickle.
Now you did most likely make minor rips and tears in the rectum walls, perhaps even deeper into the colon, there may be coffee ground black spots in your poo, or even drops of blood seeping out of your rectum or in your bowel movement. A few drops is not a major problem, it should heal.
However you do run a higher risk of bacterial infection in the blood caused by fecal bacterial that are meant to live in the colon, not your blood.
If you start presenting with symptoms like a flu or cold over the course of the next 4-5 days, see a doctor, tell him you had spots of blood in your fecal matter and hopefully you will tell him you may have ripped/tore yourself inside a little thus s/he can start you on a course of antibiotics.