Not only do doctors leave surgical tools and such inside patients, they also leave parts of the body they should've removed! There was the case of a 12 year old boy who was to have a leg removed due to bone cancer and the surgeon removed the wrong one. The same thing happened with a woman who was to have a mastectomy and the surgeon removed the wrong breast. One nurse who had to have a similar operation took the precaution of drawing a dotted line around her infected breast and wrote, "Please remove THIS one!" on it. I hate to think of what might have happened when I had my vasectomy.
Its not only doctors who do dumb things with the human body, sometimes its what we do to ourselves. My wife is an RN and she's told me some stories...man! One patient had to catheterized for a procedure and, for some perverse reason, liked it. When he went home he started putting things up his penis. Several months later he returned to the hospital with pus dripping from his member. X-rays revealed a (get this) tire pressure checking tool in his bladder

And that's only one story.
My dad went in for minor procedure one day and just before they started his doctor excused himself saying he had to go the bathroom and rushed out. Everyone figured, "When you gotta go, you gotta go!", so they waited....and waited...and waited. Finally a male nurse was sent to find him and he did...still sitting on the toilet, dead from a cocaine overdose!!!

Stories like these don't exactly make me feel all warm and secure whenever I'm in a hospital.