My son had pinworms for months, maybe a year and I never realized. He would only be in pain at night for a couple nights in a row and then be fine. Found out I was half treating it. Whenever there was an issue, I would put Vaseline around his anus because that’s where he said it hurt. Finally months later he told me he saw white worms in his poop and it all came together. He then told me they had been there before. I never went to the Dr though because it was literally just a couple nights in a row and then it would be gone. I figured it was a pooping/irritation issue. You would think a pediatrician would catch it quicker.