I had a hernia, and currently have one two. The first one I was just playing kickball all of the sudden and I suddenly got a painful feeling. My intensine fell through an unhealed muscle wall and made it way to my scrotum. Luckily it didnt't make it that far, and the only thing that made me feel sick after that was anethesia. The type of hernia I got was an inguanal (sp?) hernia. It's basically where the intensine falls through a hole where your muscle is suppose to be. Whenever men have their balls drop, sometimes the muscle wall doesn't repair itself.
My current hernia doesn't hurt, but it just feels / looks weird. It usually goes back to where it belongs when I lay down. But if I start to move, run, etc, it will "fall back down". When I had surgery, I was walking the next day. It didn't hurt at all, the anethesia "hurt" more for me.