Reddit mentions of PIN-X SOLUTION 60 ML

You can use clear tape to see if they're there. While experiencing itchy bum, use the tape on your exhaust port and examine it closely for the parasite.

There's OTC medication for it. Cheap, effective and readily available. If you ever have itchy hole, may as well use it. Just ensure yours hands are always especially clean while using it so as not to reinfect yourself.