Congrats! We have also had "dead ends" with medical doctors (peds, GI, GPs......). A Physican's Assistant suggested "Reeses Pinworm" to us. It is over the counter (walmart, rite aid....), $6.99/bottle and it worked VERY well for us. She told us it use to require a prescription. A 21 day follow up dose is required for egg laying or hatching--I can't remember which.