Roundworm can cause many synptoms, including neuological ones. The only advice I can give is cleanse, and keep cleansing. You will find a whole lot of information on this forum if you read through older post. It helps to see what others have done, and you should know going in that there is no quick fix, and no one cure. For some reason, what works for one person, may not work for everyone, so that is why you see so many different protocols.
Regarding the things you are seeing on the toilet seat....not sure what those are. Honestly I have never heard or read of anyone finding that on the seat, but in the bowl, yes.
FYI, this is a very old thread, I just happened to see it. So in the future, if you are looking for more responses, you might want to post a new message so it will get more responses.