Could my 10 month old have worms, I found brown squiggly thread like things in his diaper

Take him and the diaper to the doctor. We can not diagnose over the internet.

What have you been feeding him? Could there be fibrous tissue that is being passed through. Like celery or something? Does it happen in every diaper or just after you feed him a specific thing? Going to the doctor is the best idea. If you can narrow it down you can help them a lot.