I just swallowed a small peice of plastic that was on top of a pen lid, was about an inch long, should I be worried?

Swallowed plastic. Likely will come out in stool, but to be certain f/u w/ urgent. care, ER. Go immediately if pain. Plastic will be noted on X-ray so the can follow where it is. The article below discusses the issue (in children because they swallow objects). Of note when evaluating constipation there is a medical study that uses PVC markers. Do not worry. http://www.aafp.org/afp/2005/0715/p287.htm.