Yes - in fact, pinworms are one of the most readily seen of all of the visible parasites because they live in the lower colon area and the females come out at night and lay their eggs ON the anus, the underclothing and the bedsheets.
The lower in the colon a visible parasite lives - the better it can be seen because the body does not have a good chance to break it down with digestive enzymes before it is expelled.