Question about cats and worms

[Frenchy]

I found a tiny white worm (smaller than a grain of rice) yesterday on Paddington's fur near his bum. I called my vet this morning but could only talk to one of the younger vet techs. She told me live worms don't just come out of their bums , parasites don't look like the worm I described to her. Said it must be a wound that got infected (told me a fly could have "dropped" eggs in the wound ) either on Paddy or any of my other fuzzbutts and that the worm could have ended up there.

I came home tonight to find another one, on his fur and again , near his bum. I inspected poop , but with all the litter stuck to it , and the worms I saw are so tiny , very hard to tell. Sorry for the TMI

I'm pretty sure he needs a dewormer , what do you guys think ?