OK...well, this was the part I was NOT going to give details about! A lot of peds will say, "they don't usually go into the vaginal canal and you can only find them at night". Well, let me say I have found them in EVERY orifice of both of my daughters (if you catch the way my Catholic-shy-upbringing is drifting!) and at ALL times of the day. Yes, typically pinworms are most active at night when the child is lying still. They live in the lower intestine. The females crawl out through the anus to lay eggs (yes, it is GROSS!), then return to the lower intestine. However, occasionally, one might wander back the wrong way. Also, typically, the child experiences extreme anal itching. This is also not ALWAYS the case. I've discovered them on my kids with NO complaints....I just got in the habit of checking them for a while a few years ago because we had a problem for a couple months with reinfestation. They are about 1/4" long, skinny, white worms. The good news is that Wal-Mart actually has an over-the-counter remedy called Pin-X. There is also a prescription for Vermox through your ped. Now....again...I know this was a long shot....but your poor little girl has been on my mind. And it was a long shot several years ago with my little relative...but it turned out to be the case.