DS recently got pinworms from school. We ended up doing two rounds of PinX, an over the counter pinworm medication. His last dose was about 10 days ago. We did it twice, 10 days apart, and the entire family did it. He still has pinworms in his bm's. Should I assume the medication didn't work? How long before you no longer see them in bm's? So frustrating...
You're seeing pinworms in the bm? It's really rare to see them in stool. They usually diagnose with a tape test (to trap the eggs). I'm wondering what you're seeing? Did a test confirm they were pinworms? It could be something benign or a different type of parasite. If you tell me what it looks like I'll try to help if you need that. My son is the king of parasites so I think I've learned a lot.
On the pinworms, they can live on bedding (well the eggs hatch and then become worms) up to two weeks. So you'd want another treatment past that point. We washed sheets at each treatment point as well. I can't remember exactly but my initial though in reading your OP was 10 days was too soon if I recall what we did. But, again, I don't think you'd be seeing pinworms in the stool so I'm wondering what you have.