I have been personally insulted by my family MD while dealing with a family pinworm infestation going on for years. She insisted I was delusional and that the vermox had to work. She concluded based on negative stool samples that I did not have worms. That's odd because in veterinary medicine I just came across an article for pinworms in horses say stool samples fail to diagnose pinworms due to the way they lay eggs intermitently. I also said they were resistant to the vermox and what do you know---- dr. said no.... Vets says Yes. Pinworms are becoming immune to drugs. HUH...